drivers/rtc/rtc-at91rm9200.c: correct alarm over day/month wrap

commit eb3c227289840eed95ddfb0516046f08d8993940 upstream.

Update month and day of month to the alarm month/day instead of current
day/month when setting the RTC alarm mask.

Signed-off-by: Linus Pizunski <linus@narrativeteam.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>