Changes are:
- Run ADC on PCLK/16.
- Verify and optimize timings (ADC_STAB_DELAY_US, ADC_SAMPLETIME_DEFAULT).
- Add support for STM32H5 VBAT and COREVDD channels on ADC2.
- Replace ADC constants in machine_adc_locals_dict_table.
- Convert STM32 literal to channel numbers in adc_config_channel with
corresponding STM32 LL library functions (__LL_ADC_IS_CHANNEL_INTERNAL(),
__LL_ADC_CHANNEL_TO_DECIMAL_NB()).
Reasoning for the second last point: the STM32 driver literals are uint32_t
that don't work with MP_ROM_INT() which handles signed 31 bit integers
only. Introduce enumerator machine_adc_internal_ch_t to define external
channels (0..19), internal channels (256..) and the special channel VREF
(0xffff). Values are converted to STM32 literals with adc_ll_channel()
when required in adc_config_and_read_u16().
Signed-off-by: Rene Straub <rene@see5.ch>
72ef2e6291