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rtc: pcf2127: Disable time stamping support

Ghost User requested to merge github/fork/iluminat23/fix/REVPI-3644/connect_4_watchdog into revpi-6.1

Created by: iluminat23

For the watchdog to work all interrupt flags need to be cleared. If any interrupt flag is set the watchdog counter will stop at 1 and will not trigger a watchdog reset.

The timestamp feature of the PCF2127/PCF2129 can set two different interrupt flags. The TSF1 is set when the TS input is driven to an intermediate level between power supply and ground. And the TSF2 is set when TS input is driven to ground.

When the main power is removed and the power switches to the battery this bit might get set. It is unclear why this happens as neither the condition for TSF2 or TSF1 should apply in this case. The TS has an internal pull-up. If the TS pin in not connected should always have the same level as the power supply. And the current on the TS pin should never drop to ground level.

The second assumption, about the TSF2 seems to be true. But the TSF1 is set after a power cycle (on some devices). And this prevents a reliable use of the watchdog.

Disable the time stamping feature for now. As we don't have any device which has the TS connected. This is needed for the Connect 4 watchdog to work properly.

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