On some boards, the PCF85263 RTC does not count between reboots. Due to STOP_ENABLE (register 0x2E), bit=0 = 1, which freezes the RTC counter.
The exact trigger is unknown - not all boards exhibit the issue. The bit is battery-backed and
persists across reboots, so once set (e.g. by a power glitch or undefined hardware state) the
RTC stays frozen until explicitly cleared. The old driver never did this.
Fix: write `0x00` to `STOP_ENABLE` on init, which is the correct reset value per the datasheet.
Fix: set time properly:
Due to datasheet the set_time should be as follow:
1. set stop_enable
2. clear prescaler
3. set time
4. clear stop_enable
Signed-off-by: Marin Doetterer <marin@auterion.com>