STM32 ADCv4 driver.

Driver capability:

- Supports the STM32 "fast" ADC found on H7 sub-family.

The file registry must export:

STM32_HAS_ADCx                  - ADCx presence flag (1..4).
STM32_ADC12_HANDLER              - IRQ vector name for ADC1 and ADC2.
STM32_ADC12_NUMBER               - IRQ vector number for ADC1 and ADC2.
STM32_ADC34_HANDLER              - IRQ vector name for ADC3 and ADC4.
STM32_ADC34_NUMBER               - IRQ vector number for ADC3 and ADC4.