rtc: qpnp-rtc: Set alarm control register properly

RTC Alarm enable bit does not get conserved during
RTC probe function. This patch fixes that issue.

CRs-Fixed: 636652
Change-Id: I28203b8e301510d34d2e726c0bd25e78737f7524
Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org>
diff --git a/drivers/rtc/qpnp-rtc.c b/drivers/rtc/qpnp-rtc.c
index d64b577..de86577 100644
--- a/drivers/rtc/qpnp-rtc.c
+++ b/drivers/rtc/qpnp-rtc.c
@@ -553,8 +553,15 @@
 		goto fail_rtc_enable;
 	}
 
+	rc = qpnp_read_wrapper(rtc_dd, &rtc_dd->alarm_ctrl_reg1,
+				rtc_dd->alarm_base + REG_OFFSET_ALARM_CTRL1, 1);
+	if (rc) {
+		dev_err(&spmi->dev,
+			"Read from  Alarm control reg failed\n");
+		goto fail_rtc_enable;
+	}
 	/* Enable abort enable feature */
-	rtc_dd->alarm_ctrl_reg1 = BIT_RTC_ABORT_ENABLE;
+	rtc_dd->alarm_ctrl_reg1 |= BIT_RTC_ABORT_ENABLE;
 	rc = qpnp_write_wrapper(rtc_dd, &rtc_dd->alarm_ctrl_reg1,
 			rtc_dd->alarm_base + REG_OFFSET_ALARM_CTRL1, 1);
 	if (rc) {