brcm63xx: fix build with GCC 8.3

Fixes the following build error when building when using GCC 8.3:

In file included from ./include/linux/string.h:19,
                 from ./include/linux/bitmap.h:9,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/mips/include/asm/processor.h:15,
                 from ./arch/mips/include/asm/thread_info.h:16,
                 from ./include/linux/thread_info.h:38,
                 from ./include/asm-generic/preempt.h:5,
                 from ./arch/mips/include/generated/asm/preempt.h:1,
                 from ./include/linux/preempt.h:81,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/mmzone.h:8,
                 from ./include/linux/bootmem.h:8,
                 from arch/mips/bcm63xx/prom.c:10:
arch/mips/bcm63xx/prom.c: In function 'prom_init':
./arch/mips/include/asm/string.h:162:11: error: '__builtin_memcpy' forming offset [2, 32] is out of the bounds [0, 1] of object 'bmips_smp_movevec' with type 'char' [-Werror=array-bounds]
   __ret = __builtin_memcpy((dst), (src), __len); \
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/mips/bcm63xx/prom.c:97:3: note: in expansion of macro 'memcpy'
   memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
   ^~~~~~
In file included from arch/mips/bcm63xx/prom.c:14:
./arch/mips/include/asm/bmips.h:80:13: note: 'bmips_smp_movevec' declared here
 extern char bmips_smp_movevec;

Reported-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/target/linux/brcm63xx/patches-4.14/150-MIPS-bmips-mark-exception-vectors-as-char-arrays.patch b/target/linux/brcm63xx/patches-4.14/150-MIPS-bmips-mark-exception-vectors-as-char-arrays.patch
new file mode 100644
index 0000000000..11d79ea21c
--- /dev/null
+++ b/target/linux/brcm63xx/patches-4.14/150-MIPS-bmips-mark-exception-vectors-as-char-arrays.patch
@@ -0,0 +1,93 @@
+From badf0fc9f7dc72d06a47357123c7d97dc45792f5 Mon Sep 17 00:00:00 2001
+From: Jonas Gorski <jonas.gorski@gmail.com>
+Date: Tue, 15 Oct 2019 23:27:10 +0200
+Subject: [PATCH v2] MIPS: bmips: mark exception vectors as char arrays
+
+The vectors span more than one byte, so mark them as arrays.
+
+Fixes the following build error when building when using GCC 8.3:
+
+In file included from ./include/linux/string.h:19,
+                 from ./include/linux/bitmap.h:9,
+                 from ./include/linux/cpumask.h:12,
+                 from ./arch/mips/include/asm/processor.h:15,
+                 from ./arch/mips/include/asm/thread_info.h:16,
+                 from ./include/linux/thread_info.h:38,
+                 from ./include/asm-generic/preempt.h:5,
+                 from ./arch/mips/include/generated/asm/preempt.h:1,
+                 from ./include/linux/preempt.h:81,
+                 from ./include/linux/spinlock.h:51,
+                 from ./include/linux/mmzone.h:8,
+                 from ./include/linux/bootmem.h:8,
+                 from arch/mips/bcm63xx/prom.c:10:
+arch/mips/bcm63xx/prom.c: In function 'prom_init':
+./arch/mips/include/asm/string.h:162:11: error: '__builtin_memcpy' forming offset [2, 32] is out of the bounds [0, 1] of object 'bmips_smp_movevec' with type 'char' [-Werror=array-bounds]
+   __ret = __builtin_memcpy((dst), (src), __len); \
+           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+arch/mips/bcm63xx/prom.c:97:3: note: in expansion of macro 'memcpy'
+   memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
+   ^~~~~~
+In file included from arch/mips/bcm63xx/prom.c:14:
+./arch/mips/include/asm/bmips.h:80:13: note: 'bmips_smp_movevec' declared here
+ extern char bmips_smp_movevec;
+
+Fixes: 18a1eef92dcd ("MIPS: BMIPS: Introduce bmips.h")
+Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
+---
+
+v1 -> v2:
+ * Actually update the callers as well, to not break the build in a
+   different way.
+
+ arch/mips/bcm63xx/prom.c      |  2 +-
+ arch/mips/include/asm/bmips.h | 10 +++++-----
+ arch/mips/kernel/smp-bmips.c  |  8 ++++----
+ 3 files changed, 10 insertions(+), 10 deletions(-)
+
+--- a/arch/mips/bcm63xx/prom.c
++++ b/arch/mips/bcm63xx/prom.c
+@@ -84,7 +84,7 @@ void __init prom_init(void)
+ 		 * Here we will start up CPU1 in the background and ask it to
+ 		 * reconfigure itself then go back to sleep.
+ 		 */
+-		memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
++		memcpy((void *)0xa0000200, bmips_smp_movevec, 0x20);
+ 		__sync();
+ 		set_c0_cause(C_SW0);
+ 		cpumask_set_cpu(1, &bmips_booted_mask);
+--- a/arch/mips/include/asm/bmips.h
++++ b/arch/mips/include/asm/bmips.h
+@@ -75,11 +75,11 @@ static inline int register_bmips_smp_ops
+ #endif
+ }
+ 
+-extern char bmips_reset_nmi_vec;
+-extern char bmips_reset_nmi_vec_end;
+-extern char bmips_smp_movevec;
+-extern char bmips_smp_int_vec;
+-extern char bmips_smp_int_vec_end;
++extern char bmips_reset_nmi_vec[];
++extern char bmips_reset_nmi_vec_end[];
++extern char bmips_smp_movevec[];
++extern char bmips_smp_int_vec[];
++extern char bmips_smp_int_vec_end[];
+ 
+ extern int bmips_smp_enabled;
+ extern int bmips_cpu_offset;
+--- a/arch/mips/kernel/smp-bmips.c
++++ b/arch/mips/kernel/smp-bmips.c
+@@ -457,10 +457,10 @@ static void bmips_wr_vec(unsigned long d
+ 
+ static inline void bmips_nmi_handler_setup(void)
+ {
+-	bmips_wr_vec(BMIPS_NMI_RESET_VEC, &bmips_reset_nmi_vec,
+-		&bmips_reset_nmi_vec_end);
+-	bmips_wr_vec(BMIPS_WARM_RESTART_VEC, &bmips_smp_int_vec,
+-		&bmips_smp_int_vec_end);
++	bmips_wr_vec(BMIPS_NMI_RESET_VEC, bmips_reset_nmi_vec,
++		bmips_reset_nmi_vec_end);
++	bmips_wr_vec(BMIPS_WARM_RESTART_VEC, bmips_smp_int_vec,
++		bmips_smp_int_vec_end);
+ }
+ 
+ struct reset_vec_info {