rtc: rtc-twl4030 don't mask alarm interrupts on suspend

This patch enables the alarm interrupt of TWL4030 RTC to wake up the
system from suspend. You can test this patch with following command.

# echo +10 > /sys/class/rtc/rtc0/wakealarm; echo mem > /sys/power/state;

Signed-off-by: Kim Kyuwon <[e-mail]>
Acked-by: David Brownell <[e-mail]>
Cc: Kyungmin Park <[e-mail]>
Cc: Alessandro Zummo <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/rtc/rtc-twl4030.c

···
 {
 	irqstat = rtc_irq_bits;
 
-	/* REVISIT alarm may need to wake us from sleep */
-	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M |
-			 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
 	return 0;
 }