rtc: at91rm9200 fixes

Fix two new-ish runtime warnings in the at91rm9200 (etc) RTC:

 Platform driver 'at91_rtc' needs updating - please use dev_pm_ops
 	... by just switching

 IRQ 1/at91_rtc: IRQF_DISABLED is not guaranteed on shared IRQs
 	... no longer needed now that rtc_update_irq() changed

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>