Merge changes from topic "spm-secondary-cores" into integration

* changes:
  SPMC: embed secondary core ep info into to SPMC context
  SPMC: manifest changes to support multicore boot
  SPMD: secondary cores PM on and off SPD hooks relayed to SPMC
  SPMD: handle SPMC message to register secondary core entry point
  SPMD: introduce SPMC to SPMD messages
  SPMD: register the SPD PM hooks
  SPMD: add generic SPD PM handlers
  SPMD: enhance SPMC internal boot states
  SPMD: entry point info get helper