Bug 240384

I failed to build this port on post-build phrase, here is the relevant error log:

--- post-build ---
mkimage -n rk3399 -T rksd -d /usr/local/share/linux-rkbin/bin/rk33/rk3399_ddr_800MHz_v1.23.bin /usr/ports/sysutils/u-boot-rockpro64/work/u-boot-2019.07/idbloader.img
Image Type:   Rockchip RK33 (SD/MMC) boot image
Data Size:    79872 bytes
cat /usr/local/share/linux-rkbin/bin/rk33/rk3399_miniloader_v1.19.bin >> /usr/ports/sysutils/u-boot-rockpro64/work/u-boot-2019.07/idbloader.img
(cd /usr/ports/sysutils/u-boot-rockpro64/work/u-boot-2019.07 && rk-trust_merger /usr/local/share/linux-rkbin/rktrust/RK3399TRUST.ini)
ELF binary type "0" not known.
sh: rk-trust_merger: Exec format error
*** [post-build] Error code 126

make: stopped in /usr/ports/sysutils/u-boot-rockpro64
1 error

make: stopped in /usr/ports/sysutils/u-boot-rockpro64

I'm running 12.0-RELEASE on amd64.

The reason why I'm trying to build this manually is because I want to make a similar port for rockpi4 which is also a good SBC build on RK3399, the defconfig is already in uboot repo, It only need to change the board config line to rock-pi-4-rk3399_defconfig.
Could any add this port to the tree, since I'm don't know how to add a new port to the tree.