s390x/kvm: add etoken facility

Provide the etoken facility. We need to handle cpu model, migration and
clear reset.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20180731090448.36662-3-borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
6 files changed