rtc: ab-eoz9: fix abeoz9_rtc_read_alarm

rtc: ab-eoz9: fix abeoz9_rtc_read_alarm

abeoz9_rtc_read_alarm assumes we always read the alarm in 12-hour mode
while abeoz9_rtc_set_alarm will always set it in 24-hour mode.

We could support 12-hour mode in both functions but it seems very unlikely
that the RTC would be set to 12-hour mode now as the driver has been
setting it to 24-hour mode for a while now. The setting is undefined at
power-up and unchanged by subsequent resets which doesn't help us.

Link: https://lore.kernel.org/r/20241112151119.3451611-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>