SWDEV-292820 - Add a new notify lock

HSA signal calback may occur during the actual marker submit. That
may cause a deadlock, because shared lock_ object. Create the new
notify_lock_ field to protect the notification.

Change-Id: I9752af84e59895530620fac3932c6fc276de8658

rocclr/platform/command.cpp

@@ -265,7 +265,7 @@ bool Event::awaitCompletion() {
 bool Event::notifyCmdQueue() {
   HostQueue* queue = command().queue();
   if (AMD_DIRECT_DISPATCH) {
-    ScopedLock l(lock_);
+    ScopedLock l(notify_lock_);
     if ((status() > CL_COMPLETE) && (nullptr != queue) &&
         // If HW event was assigned, then notification can be ignored, since a barrier was issued
         (HwEvent() == nullptr) &&