efi_loader: observe CONFIG_EFI_LOADER_HII

If EFI_LOADER_HII is not set, do not unnecessarily compile files for HII
protocols.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index 4e90a35..e6bbe43 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -24,7 +24,7 @@
 obj-y += efi_device_path_to_text.o
 obj-y += efi_device_path_utilities.o
 obj-y += efi_file.o
-obj-y += efi_hii.o efi_hii_config.o
+obj-$(CONFIG_EFI_LOADER_HII) += efi_hii.o efi_hii_config.o
 obj-y += efi_image_loader.o
 obj-y += efi_memory.o
 obj-y += efi_root_node.o