sandbox: enable support for the unlz4 command

This does not work with sandbox at present. Fix it up to use map_sysmem()
to convert an address to a pointer.

Signed-off-by: Jonathan Liu <net147@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Fix conflict and reformat to 80cols:
Signed-off-by: Simon Glass <sjg@chromium.org>
1 file changed