fix(sptool): update Optee FF-A manifest

Change the OPTEE FF-A manifest to comply with changes to the sp pkg [1].
The sptool packs the image at the default offset of 0x4000, if it is not
provided in the arguments.

[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/14507

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I647950410114f7fc24926696212bb7f8101390ac
1 file changed