rockchip: RK322x: Select SPL_OPTEE_IMAGE

For RK322x series ARM SoCs the OP-TEE is non-optional, as besides the TEE
it also provides the PSCI implementation, which is expected to be available
by upstream linux.

Select CONFIG_SPL_OPTEE_IMAGE if an FIT image is built.

Signed-off-by: Alex Bee <knaerzche@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>