We package U-Boot and OP-TEE into one itb file for SPL, so that we can support OP-TEE in SPL. Signed-off-by: Kever Yang <kever.yang@rock-chips.com> Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>