Merge changes from topic "mp/ffa_v1_1_eac"

* changes:
  fix: serialize powering on secondary CPUs
  fix(interrupts): deny new direct request message from endpoint
  test(interrupts): command to resume after managed exit
  test(interrupts): hint fwd destination SP could be interrupted
  fix(interrupts): dont enable virtual maintenance interrupts
  test(interrupts): managed exit supported by second SP
  test(interrupts): managed exit supported by first SP
  test(interrupts): exercise managed exit by two SPs in a call chain
  test(interrupts): exercise ns interrupt being queued
  test(interrupts): exercise ns interrupt being signaled to SP
  feat(interrupts): resume interrupted target vCPU
  feat(interrupts): add support for handling managed exit through vIRQ
  feat(interrupts): discover interrupt ID of managed exit signal
  feat(interrupts): specify action in response to ns interrupt in manifest
  fix(direct message request): incorrect response for illegal transition