griffin: time_daemon: use /persist to store offset to RTC

Change-Id: Ieaa9c9308a4004eeb92027b71999359ea47e5fd8
Signed-off-by: Wei Wang <wvw@google.com>
Signed-off-by: Erfan Abdi <erfangplus@gmail.com>

vendor.prop

@@ -245,6 +245,7 @@ persist.sys.ssr.restart_level=ALL_ENABLE
 
 ## Time Service
 persist.timed.enable=true
+persist.delta_time.enable=true
 
 ## Vendor Extension
 ro.vendor.extension_library=libqti-perfd-client.so