platform: msm_shared: add support for checking alarmboot mode

When the phone is triggered by alarm, it's required to turn off
the display during booting until the alarm app is invoked. So add
the function to check device if it's alarm boot.

Change-Id: I4eca894753dd47095dca93958a29c19476f42382
diff --git a/platform/init.c b/platform/init.c
index 34c5726..13612b7 100644
--- a/platform/init.c
+++ b/platform/init.c
@@ -145,3 +145,8 @@
 {
 	return 0;
 }
+
+__WEAK uint32_t check_alarm_boot()
+{
+	return 0;
+}