efi_loader: typedef efi_string_t text output protocol

We do not want to use typedefs in U-Boot.

Do not use efi_string_t in the EFI_TEXT_OUTPUT_PROTOCOL.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/include/efi_api.h b/include/efi_api.h
index c635abe..df9bee2 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -701,10 +701,10 @@
 			char extended_verification);
 	efi_status_t (EFIAPI *output_string)(
 			struct efi_simple_text_output_protocol *this,
-			const efi_string_t str);
+			const u16 *str);
 	efi_status_t (EFIAPI *test_string)(
 			struct efi_simple_text_output_protocol *this,
-			const efi_string_t str);
+			const u16 *str);
 	efi_status_t(EFIAPI *query_mode)(
 			struct efi_simple_text_output_protocol *this,
 			unsigned long mode_number, unsigned long *columns,