s390x/s390-virtio-ccw: add zpcii-disable machine property

s390x/s390-virtio-ccw: add zpcii-disable machine property

The zpcii-disable machine property can be used to force-disable the use
of zPCI interpretation facilities for a VM.  By default, this setting
will be off for machine 7.2 and newer.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20220902172737.170349-9-mjrosato@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
[thuth: Fix contextual conflict in ccw_machine_7_1_instance_options()]
Signed-off-by: Thomas Huth <thuth@redhat.com>