pm: change system time restore source priority

pm: change system time restore source priority

Changed preference for restoring system time after resume
to persistent clock -> suspend-nonstop clocksource -> rtc

This is required as suspend-nonstop clocksource does not report
proper time after resume.
Change to be reverted once suspend-nonstop clocksource is fixed.

Bug 200258431

Change-Id: If9f021841a5aa738980f7b393f68c207aaf155d2
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Reviewed-on: http://git-master/r/1302179
GVS: Gerrit_Virtual_Submit
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
Reviewed-by: Joseph Lo <josephl@nvidia.com>
Tested-by: Joseph Lo <josephl@nvidia.com>
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>