hwmon: (pmbus/adm1275) Disable ADC while updating PMON_CONFIG

According to ADI, changing PMON_CONFIG while the ADC is running can have
unexpected results. ADI recommends halting the ADC with PMON_CONTROL
before setting PMON_CONFIG and then resume after. Follow ADI
recommendation and disable ADC while PMON_CONFIG is updated.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230614163605.3688964-3-linux@roeck-us.net


Signed-off-by: Guenter Roeck <linux@roeck-us.net>