rtc: pcf2127: fix watchdog interrupt mask on pcf2131

When using interrupt pin (INT A) as watchdog output all other
interrupt sources need to be disabled to avoid additional
resets. Resulting INT_A_MASK1 value is 55 (0x37).

Signed-off-by: Bruno Thomsen <bruno.thomsen@gmail.com>
Link: https://lore.kernel.org/r/20250902182235.6825-1-bruno.thomsen@gmail.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>