alpha, rtc: Change to use rtc_class_ops's set_mmss64()

Change alpha_rtc_set_mmss() and remote_set_mmss() to use
rtc_class_ops's set_mmss64(), to be y2038 safe.

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>
Cc: Richard Henderson <rth@twiddle.net>
Link: http://lkml.kernel.org/r/1427945681-29972-15-git-send-email-john.stultz@linaro.org


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