efi: Allow inclusion of EFI-runtime headers

Some headers use the __efi_runtime macro in their declarations. With the
app we do not have a separate runtime sections, so define this to be
empty. This allows the headers to be included from the app.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/efi.h

@@ -58,6 +58,11 @@ struct udevice;
 #define EFI32_LOADER_SIGNATURE	"EL32"
 #define EFI64_LOADER_SIGNATURE	"EL64"
 
+#ifdef CONFIG_EFI_APP
+/* add an empty value for this so that efi_variables.h can be included */
+#define __efi_runtime
+#endif
+
 /**
  * struct efi_device_path - device path protocol
  *