[ARM] 3745/1: Add EXPORT_SYMBOL(rtc_next_alarm_time) to ARM rtctime.c

Patch from George G. Davis

Fix "WARNING: "rtc_next_alarm_time" [drivers/rtc/rtc-sa1100.ko]
undefined!"

Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>