efi: Add start-up library code

When running as an EFI application, U-Boot must request memory from EFI,
and provide access to the boot services U-Boot needs.

Add library code to perform these tasks. This includes efi_main() which is
the entry point from EFI. U-Boot is built as a shared library.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/lib/efi/Makefile b/lib/efi/Makefile
new file mode 100644
index 0000000..5ee344c
--- /dev/null
+++ b/lib/efi/Makefile
@@ -0,0 +1,7 @@
+#
+# (C) Copyright 2015 Google, Inc
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_EFI_APP) += efi_app.o efi.o