efi_loader: TPL_HIGH_LEVEL not allowed for CreateEvent

According to chapter 7.1 "Event, Timer, and Task Priority Services"
TPL_HIGH_LEVEL should not be exposed to applications and drivers.

According to the discussion with EDK II contributors this implies that
CreateEvent() shall not allow to create events with TPL_HIGH_LEVEL.

Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 4777b35..f6d5ba0 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -264,7 +264,6 @@
 	case TPL_APPLICATION:
 	case TPL_CALLBACK:
 	case TPL_NOTIFY:
-	case TPL_HIGH_LEVEL:
 		return EFI_SUCCESS;
 	default:
 		return EFI_INVALID_PARAMETER;
diff --git a/lib/efi_selftest/efi_selftest_tpl.c b/lib/efi_selftest/efi_selftest_tpl.c
index 70a355e..0c0e412 100644
--- a/lib/efi_selftest/efi_selftest_tpl.c
+++ b/lib/efi_selftest/efi_selftest_tpl.c
@@ -55,7 +55,7 @@
 		return EFI_ST_FAILURE;
 	}
 	ret = boottime->create_event(EVT_TIMER | EVT_NOTIFY_WAIT,
-				     TPL_HIGH_LEVEL, notify, NULL, &event_wait);
+				     TPL_NOTIFY, notify, NULL, &event_wait);
 	if (ret != EFI_SUCCESS) {
 		efi_st_error("could not create event\n");
 		return EFI_ST_FAILURE;