x86: dts: Add a device tree file for EFI

This contains just enough to bring up the serial UART.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/dts/Makefile b/arch/x86/dts/Makefile
index 44e2829..71595c7 100644
--- a/arch/x86/dts/Makefile
+++ b/arch/x86/dts/Makefile
@@ -2,6 +2,7 @@
 	chromebook_link.dtb \
 	chromebox_panther.dtb \
 	crownbay.dtb \
+	efi.dtb \
 	galileo.dtb \
 	minnowmax.dtb \
 	qemu-x86_i440fx.dtb \