rtc: rtc-sh: fix for period rtc interrupts.
rtc: rtc-sh: fix for period rtc interrupts.

When testing the per second interrupt support (RTC_UIE_ON/RTC_UIE_OFF)
of the new RTC system it would die in sh_rtc_interrupt due to a null
ptr dereference. The following gets it working correctly.

Signed-off-by: Jamie Lenehan <11f44a25e06ca3c9b1f620cc4299de63d7937d30@twibble.org>
Signed-off-by: Paul Mundt <38b52dbb5f0b63d149982b6c5de788ec93a89032@linux-sh.org>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas