Merge changes I2fcf13b7,I153ccb43 into integration

* changes:
feat(n1sdp): add support for nt_fw_config
feat(n1sdp): enable trusted board boot on n1sdp

feat(n1sdp): enable trusted board boot on n1sdp

Move from RESET_TO_BL31 boot to a TBBR style boot on N1sdp.

Signed-off-by: sahil <sahil@arm.com>
Change-Id: I153ccb43a4a013830973c7a183825d62b372c65e