All of the command files have moved to cmd directory, add description to
Directory Hierarchy.
Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
/x86 Files generic to x86 architecture
/api Machine/arch independent API for external apps
/board Board dependent files
+/cmd U-Boot commands functions
/common Misc architecture independent functions
/configs Board default configuration files
/disk Code for disk drive partition handling