configure saradc2 controller
| MEAS2_DATA_SAR | SAR ADC2 data |
| MEAS2_DONE_SAR | SAR ADC2 conversion done indication |
| MEAS2_START_SAR | SAR ADC2 controller (in RTC) starts conversion |
| MEAS2_START_FORCE | 1: SAR ADC2 controller (in RTC) is started by SW |
| SAR2_EN_PAD | SAR ADC2 pad enable bitmap |
| SAR2_EN_PAD_FORCE | 1: SAR ADC2 pad enable bitmap is controlled by SW |