spl: fit: Add ability to jump to Linux via OPTEE-OS on ARMv7a

spl: fit: Add ability to jump to Linux via OPTEE-OS on ARMv7a

Add support for jumping to Linux kernel through OPTEE-OS on ARMv7a to SPL.
This is already supported on ARMv8a, this patch adds the ARMv7a support.
Extend the SPL fitImage loader to record OPTEE-OS load address and in case
the load address is non-zero, use the same bootm-optee.S code used by the
U-Boot fitImage jump code to start OPTEE-OS first and jump to Linux next.

Signed-off-by: Marek Vasut <marek.vasut@mailbox.org>