This prepares for the creation of a u-boot-rockchip-spi.bin image similar to u-boot-rockchip.bin to the exception it's destined for SPI-NOR flashes instead of MMC storage medium. Cc: Quentin Schulz <foss+uboot@0leil.net> Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Kever Yang <kever.yang@rock-chips.com>