Merge changes from topic "ffa_el3_spmc" into integration

* changes:
  feat(spmc): add helper to obtain a partitions FF-A version
  feat(spmd): enable SPMD to forward FFA_VERSION to EL3 SPMC
  feat(spmc): enable handling FFA_VERSION ABI
  feat(spmc): add helper function to obtain endpoint mailbox
  feat(spmc): add helper function to obtain hyp structure
  feat(spmc): enable parsing of messaging methods from manifest