arm/arm64: ITS: pending table migration test

Add two new migration tests. One testing the migration of
a topology where collection were unmapped. The second test
checks the migration of the pending table.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
[ Complete migration even when the test is skipped. Otherwise the
  migration scripts hang. Also, without the KVM fix for unmapped
  collections, migration will fail and the test will hang, so use
  errata to skip it instead. ]
Signed-off-by: Andrew Jones <drjones@redhat.com>