cmd: Add dtimg command

dtimg command allows user to work with Android DTB/DTBO image format.
Such as, getting the address of desired DTB/DTBO file, printing the dump
of the image in U-Boot shell, etc.

This command is needed to provide Android boot with new Android DT image
format further.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index d5abcfd..51db3da 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -254,6 +254,14 @@
 	help
 	  Add an ANSI terminal boot menu command.
 
+config CMD_DTIMG
+	bool "dtimg"
+	help
+	  Android DTB/DTBO image manipulation commands. Read dtb/dtbo files from
+	  image into RAM, dump image structure information, etc. Those dtb/dtbo
+	  files should be merged in one dtb further, which needs to be passed to
+	  the kernel, as part of a boot process.
+
 config CMD_ELF
 	bool "bootelf, bootvx"
 	default y