efi_loader: implement EFI_DEVICE_PATH_TO_TEXT_PROTOCOL

ConvertPathToText is implemented for
* type 4    - media device path
* subtype 4 - file path

This is the kind of device path we hand out for block devices.

All other cases may be implemented later.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
[agraf: fix whitespace]
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index fa8b91a..3fc2371 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -15,7 +15,7 @@
 
 obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o
 obj-y += efi_image_loader.o efi_boottime.o efi_runtime.o efi_console.o
-obj-y += efi_memory.o
+obj-y += efi_memory.o efi_device_path_to_text.o
 obj-$(CONFIG_LCD) += efi_gop.o
 obj-$(CONFIG_PARTITIONS) += efi_disk.o
 obj-$(CONFIG_NET) += efi_net.o