efi_loader: make EFI_DT_FIXUP_PROTOCOL configurable

Allow EFI_DT_FIXUP_PROTOCOL to be disabled via configuration.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/efi_dt_fixup.c b/lib/efi_loader/efi_dt_fixup.c
index c2f2dae..3850ab3 100644
--- a/lib/efi_loader/efi_dt_fixup.c
+++ b/lib/efi_loader/efi_dt_fixup.c
@@ -104,10 +104,9 @@
  * @flags:		bit field designating action to be performed
  * Return:		status code
  */
-static efi_status_t EFIAPI efi_dt_fixup(struct efi_dt_fixup_protocol *this,
-					void *dtb,
-					efi_uintn_t *buffer_size,
-					u32 flags)
+static efi_status_t __maybe_unused EFIAPI
+efi_dt_fixup(struct efi_dt_fixup_protocol *this, void *dtb,
+	     efi_uintn_t *buffer_size, u32 flags)
 {
 	efi_status_t ret;
 	size_t required_size;