drivers/rtc/rtc-twl.c: simplify RTC interrupt clearing

For clearing RTC interrupt, programming ALARM bit only is sufficient, as
all other bits are any way not affected by writing 0 to them.

Hence removed unwanted OR operation.

Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-twl.c

@@ -384,7 +384,7 @@ static irqreturn_t twl_rtc_interrupt(int irq, void *rtc)
 	else
 		events |= RTC_IRQF | RTC_UF;
 
-	res = twl_rtc_write_u8(rd_reg | BIT_RTC_STATUS_REG_ALARM_M,
+	res = twl_rtc_write_u8(BIT_RTC_STATUS_REG_ALARM_M,
 				   REG_RTC_STATUS_REG);
 	if (res)
 		goto out;