HV: Use NMI to replace INIT signal for lapic-pt VMs S5

We have implemented a new notification method using NMI.
So replace the INIT notification method with the NMI one.
Then we can remove INIT notification related code later.

Tracked-On: #3886
Signed-off-by: Kaige Fu <kaige.fu@intel.com>

hypervisor/include/common/schedule.h

@@ -26,6 +26,7 @@ enum thread_object_state {
 
 enum sched_notify_mode {
 	SCHED_NOTIFY_INIT,
+	SCHED_NOTIFY_NMI,
 	SCHED_NOTIFY_IPI
 };