ARM: prima2: pm: enable rtc alarm0 and alarm1 as wakeup source

This patch also enables RTC alarm as wakeup source after system suspends.

Signed-off-by: Xianglong Du <Xianglong.Du@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Olof Johansson <olof@lixom.net>