Add support for various MCUBoot features, and move toward the eventual removal of TF-M's MCUBoot fork.
Commits:
- https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/4551
- https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/4563
- https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/4564
- https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/4565
- https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/4566