[L0 v2] make all events have HOST signal scope

We don't need this capability for the internal event
in queue_immediate_in_order but there isn't much difference
in benchmarks anyway. We might revisit this in future.

Author: igchor

source/adapters/level_zero/v2/event_provider_counter.cpp

@@ -39,7 +39,7 @@ event_allocation provider_counter::allocate() {
   if (freelist.empty()) {
     ZeStruct<ze_event_desc_t> desc;
     desc.index = 0;
-    desc.signal = 0;
+    desc.signal = ZE_EVENT_SCOPE_FLAG_HOST;
     desc.wait = 0;
     ze_event_handle_t handle;
 

source/adapters/level_zero/v2/event_provider_normal.cpp

@@ -51,7 +51,7 @@ provider_pool::provider_pool(ur_context_handle_t context,
   for (int i = 0; i < EVENTS_BURST; ++i) {
     ZeStruct<ze_event_desc_t> desc;
     desc.index = i;
-    desc.signal = 0;
+    desc.signal = ZE_EVENT_SCOPE_FLAG_HOST;
     desc.wait = 0;
     ZE2UR_CALL_THROWS(zeEventCreate, (pool.get(), &desc, freelist[i].ptr()));
   }