efi_loader: run CreateEvent() notify function based on flags

The UEFI specification states that the tpl, function and context
arguments are to be ignored if neither EVT_NOTIFY_WAIT or
EVT_NOTIFY_SIGNAL are specified.  This matches observed behaviour with
an AMI EDK2 based UEFI implementation.

Skip calling the notify function if neither flag is present.

Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Acked-By: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/include/efi_api.h b/include/efi_api.h
index 5c3836a..f071b36 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -28,6 +28,9 @@
 	EFI_TIMER_RELATIVE = 2
 };
 
+#define EVT_NOTIFY_WAIT		0x00000100
+#define EVT_NOTIFY_SIGNAL	0x00000200
+
 /* EFI Boot Services table */
 struct efi_boot_services {
 	struct efi_table_hdr hdr;