Merge changes from topic "mb/lfa-core-work" into integration
* changes:
docs(maintainers): add myself as code owner for LFA service
docs(lfa): update porting guide with LFA platform APIs
feat(lfa): add LFA holding pen logic
feat(lfa): add initial implementation for LFA_ACTIVATE
feat(lfa): add initial implementation for LFA_PRIME
feat(fvp): implement platform API for load and auth image
feat(lfa): implement LFA_CANCEL SMC
feat(fvp): implement platform API for LFA cancel operation
feat(lfa): implement LFA_GET_INVENTORY SMC
feat(fvp): implement platform API for LFA activation pending check
feat(lfa): implement LFA_GET_INFO SMC and integrate LFA build
feat(fvp): initialize LFA component activators in platform layer
feat(rmm): add placeholder activator callbacks for LFA
feat(bl31): add placeholder activator implementation for LFA
feat(lfa): add activation handler interface for component activation
feat(fvp): implement LFA get components API
feat(lfa): create LFA SMC handler template