imx8mm-cl-iot-gate-optee: align config with Kconfig

Due to missing configs, CI goes in deadlock until an OOM is tracked. Add
CONFIG_SYS_LOAD_ADDR and replace CONFIG_SYS_EXTRA_OPTIONS with
CONFIG_IMX_CONFIG.

Signed-off-by: Stefano Babic <sbabic@denx.de>
CC: Ying-Chun Liu (PaulLiu)" <paul.liu@linaro.org>
CC: Fabio Estevam <festevam@denx.de>