KVM: s390: add enhanced sort facilty to cpu model

This enables stfle.150 and adds the subfunctions for SORTL. Bit 150 is
added to the list of facilities that will be enabled when there is no
cpu model involved as sortl requires no additional handling from
userspace, e.g. for migration.

Please note that a cpu model enabled user space can and will have the
final decision on the facility bits for a guests.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>