bootm: Add a bootm command for type IH_OS_EFI

Add support for booting EFI binaries contained in FIT images.
A typical usage scenario is chain-loading GRUB2 in a verified
boot environment.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 4e29e7b..a6bfa87 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -259,6 +259,13 @@
 	help
 	  Boot an application image from the memory.
 
+config BOOTM_EFI
+	bool "Support booting UEFI FIT images"
+	depends on CMD_BOOTEFI && CMD_BOOTM && FIT
+	default y
+	help
+	  Support booting UEFI FIT images via the bootm command.
+
 config CMD_BOOTZ
 	bool "bootz"
 	help