Merge changes from topic "db/sel0"

* changes:
  SPM: S-EL0 partitions support build for TC0
  SPM: Split S-EL1 shim from S-EL0 application
  SPM: Use FF-A for message handling in Ivy
  SPM: Extract common debug code used for SPs
  SPM: Define Ivy partition manifest
  SPM: Add shim layer to Ivy partition and enable PIE
  Change vector_entry names to match tftf code style