drivers/rtc/mxc: Convert get_alarm_or_time()/set_alarm_or_time() to use time64_t

We want to convert mxc_rtc_set_mmss() to use rtc_class_ops's
set_mmss64(), but it uses get_alarm_or_time()/set_alarm_or_time()
internal interfaces which are y2038 unsafe.

So here as a separate patch, it converts these two internal
interfaces of "mxc" to use safe time64_t to make some
preparations.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-13-git-send-email-john.stultz@linaro.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>