This allows to build u-boot-rockchip.bin binary with binman for Rockchip
ARM64 boards instead of the legacy Makefile way.
Cc: Quentin Schulz <foss+uboot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>