Test attestation service with regression test suite on level 2 isolation.
Linker to fix the issue: https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/1096/ https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/1097/
Other relevant changes (fixes): https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/1090/ https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/1091/