This task is to implement SST flash interface on top of CMSIS flash driver.
Resolved by the following patches: https://review.trustedfirmware.org/#/c/62 https://review.trustedfirmware.org/#/c/63 https://review.trustedfirmware.org/#/c/64 https://review.trustedfirmware.org/#/c/65 https://review.trustedfirmware.org/#/c/66