STM32 ADCv3 driver.

Driver capability:

- Supports the STM32 "fast" ADC found on F3 and L4 sub-families.

The file registry must export:

STM32_HAS_ADCx                  - ADCx presence flag (1..4).
STM32_ADC1_HANDLER              - IRQ vector name for ADC1.
STM32_ADC1_NUMBER               - IRQ vector number for ADC1.
STM32_ADC2_HANDLER              - IRQ vector name for ADC2.
STM32_ADC2_NUMBER               - IRQ vector number for ADC2.
STM32_ADC3_HANDLER              - IRQ vector name for ADC3.
STM32_ADC3_NUMBER               - IRQ vector number for ADC3.
STM32_ADC4_HANDLER              - IRQ vector name for ADC4.
STM32_ADC4_NUMBER               - IRQ vector number for ADC4.
STM32_ADCx_DMA_MSK              - Mask of the compatible DMA channels (1..4).
STM32_ADCx_DMA_CHN              - Mask of the channels mapping (1..4).
