rtc: pcf2123: don't use weekday alarm

The week day may not be set properly by userspace. This would result is
missed alarms. Disable alarm matching on weekday.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20190819182656.29744-1-alexandre.belloni@bootlin.com


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