efi_loader: implement EFI_DT_FIXUP_PROTOCOL

A boot manager like GRUB can use the protocol to

* apply U-Boot's fix-ups to the a device-tree
* let U-Boot make memory reservations according to the device-tree
* install the device-tree as a configuration table

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/cmd/efidebug.c b/cmd/efidebug.c
index 5fb7b1e..6de81ca 100644
--- a/cmd/efidebug.c
+++ b/cmd/efidebug.c
@@ -8,6 +8,7 @@
 #include <charset.h>
 #include <common.h>
 #include <command.h>
+#include <efi_dt_fixup.h>
 #include <efi_loader.h>
 #include <efi_rng.h>
 #include <exports.h>
@@ -495,6 +496,10 @@
 		"PXE Base Code",
 		EFI_PXE_BASE_CODE_PROTOCOL_GUID,
 	},
+	{
+		"Device-Tree Fixup",
+		EFI_DT_FIXUP_PROTOCOL_GUID,
+	},
 	/* Configuration table GUIDs */
 	{
 		"ACPI table",