efi: Add support for a hello world test program

It is useful to have a basic sanity check for EFI loader support. Add a
'bootefi hello' command which loads HelloWord.efi and runs it under U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
[agraf: Fix documentation, add unfulfilled kconfig dep]
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index e339d86..ebcfd6d 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -181,6 +181,15 @@
 	help
 	  Boot an EFI image from memory.
 
+config CMD_BOOTEFI_HELLO
+	bool "Allow booting a standard EFI hello world for testing"
+	depends on CMD_BOOTEFI && NEED_CRT0_ENABLEMENT
+	help
+	  This adds a standard EFI hello world application to U-Boot so that
+	  it can be used with the 'bootefi hello' command. This is useful
+	  for testing that EFI is working at a basic level, and for bringing
+	  up EFI support on a new architecture.
+
 config CMD_ELF
 	bool "bootelf, bootvx"
 	default y