drivers: adc: add the stm32U5 devices to the adc driver

The STM32U5x device has ADC instance of different versions
similar to the stm32H7 about the oversampling.
ADC1 of 14bit resolution has a ratio from 1..1024 on OSR[9:0]
ADC4 of 12bit resolution has a ratio on OVSR[2:0]

Signed-off-by: Francois Ramu <francois.ramu@st.com>
1 file changed