Merge changes from topic "srm/Errata_ABI_El3" into integration

* changes:
  docs(errata_abi): document the errata abi changes
  feat(fvp): enable errata management interface
  fix(cpus): workaround platforms non-arm interconnect
  refactor(errata_abi): factor in non-arm interconnect
  feat(errata_abi): errata management firmware interface