stm32/adc: Update ADC driver to work with the new H7 HAL.
stm32/adc: Update ADC driver to work with the new H7 HAL.

Use NB_TO_CHANNEL to map decimal numbers to channel numbers.  And use the
correct rank to initialize channels (ADC_REGULAR_RANK_1).

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython