RTC: fix typo in drivers/rtc/rtc-at91sam9.c

The member of the rtc_class_ops struct is called alarm_irq_enable and
not alarm_irq_enabled

CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jelle Martijn Kok <jmkok@youcom.nl>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-at91sam9.c

@@ -309,7 +309,7 @@ static const struct rtc_class_ops at91_rtc_ops = {
 	.read_alarm	= at91_rtc_readalarm,
 	.set_alarm	= at91_rtc_setalarm,
 	.proc		= at91_rtc_proc,
-	.alarm_irq_enabled = at91_rtc_alarm_irq_enable,
+	.alarm_irq_enable = at91_rtc_alarm_irq_enable,
 };
 
 /*