Timesync: Make sure timesync event is setup after curTick is unserialized

Setup initial timesync event in initState or loadState so that curTick has
been updated to the new value, otherwise the event is scheduled in the past.

src/sim/root.cc

@@ -108,7 +108,18 @@ Root::Root(RootParams *p) : SimObject(p), _enabled(false),
     assert(_root == NULL);
     _root = this;
     lastTime.setTimer();
-    timeSyncEnable(p->time_sync_enable);
+}
+
+void
+Root::initState()
+{
+    timeSyncEnable(params()->time_sync_enable);
+}
+
+void
+Root::loadState(Checkpoint *cp)
+{
+    timeSyncEnable(params()->time_sync_enable);
 }
 
 Root *