efi_loader: add missing const classifier for event service

const classifier is missing in EventGroup parameter of
CreateEventEx(). Fix it to remove the compiler warning.

NotifyContext parameter of CreateEventEx() is also defined
with const in UEFI specification, but NotifyContext parameter
of CreateEvent() is defined without const.
Since current implementation calls the common efi_create_event()
function from both CreateEventEx() and CreateEvent() services,
NotifyContext parameter leaves as is.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/efi_api.h b/include/efi_api.h
index 8f5ef5f..c2d6964 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -192,7 +192,7 @@
 					struct efi_event *event,
 					void *context),
 				void *notify_context,
-				efi_guid_t *event_group,
+				const efi_guid_t *event_group,
 				struct efi_event **event);
 };
 
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 247be06..1fd7b0b 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -684,7 +684,7 @@
 			      void (EFIAPI *notify_function) (
 					struct efi_event *event,
 					void *context),
-			      void *notify_context, efi_guid_t *group,
+			      void *notify_context, const efi_guid_t *group,
 			      struct efi_event **event);
 /* Call this to set a timer */
 efi_status_t efi_set_timer(struct efi_event *event, enum efi_timer_delay type,
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 0b7579c..f9b10a9 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -712,7 +712,7 @@
 			      void (EFIAPI *notify_function) (
 					struct efi_event *event,
 					void *context),
-			      void *notify_context, efi_guid_t *group,
+			      void *notify_context, const efi_guid_t *group,
 			      struct efi_event **event)
 {
 	struct efi_event *evt;
@@ -790,7 +790,7 @@
 							struct efi_event *event,
 							void *context),
 					void *notify_context,
-					efi_guid_t *event_group,
+					const efi_guid_t *event_group,
 					struct efi_event **event)
 {
 	efi_status_t ret;