linux-imx

rtc: Staticize non-exported __rtc_set_alarm()

It's not referenced outside this file so there's no need for it to be in
the global namespace and sparse warns about that.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>