s390x/ais: for 2.10 stable: disable ais facility

s390x/ais: for 2.10 stable: disable ais facility

The migration interface for ais was introduced with kernel 4.13
but the capability itself had been active since 4.12. As migration
support is considered necessary lets disable ais in the 2.10
stable version. A proper fix and re-enablement will be done
for qemu 2.11.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20170921140834.14233-2-borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>