uboot-imx

rockchip: add fit source file for pack itb with op-tee

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>