efi_loader: helper functions for protocol management

This patch provides helper functions to manage protocols.
efi_search_protocol - find a protocol on a handle
efi_add_protocol - install a protocol on a handle
efi_remove_protocol - remove a protocol from a handle
efi_remove_all_protocols - remove all protocols from a handle

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index a5aae1b..934f64d 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -196,6 +196,18 @@
 efi_status_t efi_create_handle(void **handle);
 /* Call this to validate a handle and find the EFI object for it */
 struct efi_object *efi_search_obj(const void *handle);
+/* Find a protocol on a handle */
+efi_status_t efi_search_protocol(const void *handle,
+				 const efi_guid_t *protocol_guid,
+				 struct efi_handler **handler);
+/* Install new protocol on a handle */
+efi_status_t efi_add_protocol(const void *handle, const efi_guid_t *protocol,
+			      void *protocol_interface);
+/* Delete protocol from a handle */
+efi_status_t efi_remove_protocol(const void *handle, const efi_guid_t *protocol,
+				 void *protocol_interface);
+/* Delete all protocols from a handle */
+efi_status_t efi_remove_all_protocols(const void *handle);
 /* Call this to create an event */
 efi_status_t efi_create_event(uint32_t type, efi_uintn_t notify_tpl,
 			      void (EFIAPI *notify_function) (