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: NJamie Lenehan <lenehan@twibble.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>