init.qcom.early_boot.sh: Add ro.alarm_boot property support

ro.alarm_boot property is used to let framwork detect if it
is RTC triggered boot.

Change-Id: Id503ad39a2872fdb3acbc79233c008dc4f4e4a3c
Merge "init.qcom.early_boot.sh: Add ro.alarm_boot property support"
Merge 5eeccb7385f1a7bb397aa1eacf375d69cc94ab38 on remote branch

Change-Id: I7ae4781e00ed6093770212313e215fa058a3b4e1