efi_loader: implement InstallProtocolInterface

efi_install_protocol_interface up to now only returned an error code.

The patch implements the UEFI specification for InstallProtocolInterface
with the exception that it will not create new handles.

Signed-off-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 f071b36..42cd47f 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -58,7 +58,7 @@
 	efi_status_t (EFIAPI *signal_event)(void *event);
 	efi_status_t (EFIAPI *close_event)(void *event);
 	efi_status_t (EFIAPI *check_event)(void *event);
-
+#define EFI_NATIVE_INTERFACE	0x00000000
 	efi_status_t (EFIAPI *install_protocol_interface)(
 			void **handle, efi_guid_t *protocol,
 			int protocol_interface_type, void *protocol_interface);