drivers/rtc/rtc-max8925.c: fix alarm->enabled mistake in max8925_rtc_read_alarm/max89...

max8925_rtc_read_alarm() should set alrm->enabled based on both
ALARM_IRQ_MASK and ALARM_CTRL setting.  max8925_rtc_set_alarm() should
enable/disable alarm according to ALARM_CTRL reg setting.

Signed-off-by: Kevin Liu <kliu5@marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>