uboot-imx

ARM64: zynqmp: Use the same U-Boot version with/without ATF

Remove SECURE_IOU option which is not needed. U-Boot itself can detect
which EL level it is on and based on that use do platform setup.
It also simplify usage because one Kconfig entry is gone.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>