MdeModulePkg: Add NVMe Long Delay Time Events

Fire an event if a long delay occurs when starting an NVMe device.
This can be used by platforms to draw pictures on the screen or
take other actions to notify a user or move boot forward.

Signed-off-by: Oliver Smith-Denny <osde@linux.microsoft.com>

MdeModulePkg/Include/Guid/NVMeEventGroup.h

@@ -0,0 +1,16 @@
+/** @file
+
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef NVME_EVENT_GROUP_GUID_
+#define NVME_EVENT_GROUP_GUID_
+
+// gNVMeEnableStartEventGroupGuid is used to signal the start of enabling the NVMe controller
+extern EFI_GUID  gNVMeEnableStartEventGroupGuid;
+// gNVMeEnableCompleteEventGroupGuid is used to signal that the NVMe controller enable has finished
+extern EFI_GUID  gNVMeEnableCompleteEventGroupGuid;
+
+#endif