iio: adc: stm32-adc: add stm32mp13 support

Add STM32 ADC support for STM32MP13x SOCs family.

On STM32MP13x, each ADC peripheral has a single ADC block.
These ADC peripherals, ADC1 and ADC2, are fully independent.
This introduces changes in common registers handling.

Some features such as boost mode, channel preselection and
linear calibration are not supported by the STM32MP13x ADC.
Add diversity management for these features.

The STM32MP13x ADC introduces registers and bitfield variants
on existing features such as calibration factors and internal
channels. Add register diversity management.

Add also support for new internal channels VDDCPU and VDDQ_DDR.

Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20221012142205.13041-4-olivier.moysan@foss.st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>