domain_conf: Allow to look up virtio-block devices by their CCW address

domain_conf: Allow to look up virtio-block devices by their CCW address

On s390x, devices are accessed via the channel subsystem by default,
so we need to look up the devices via their CCW address there instead
of using PCI.

This fixes "virsh domfsinfo" on s390x for virtio-block devices (the first
attempt from commit f8333b3b0a7 did it in the wrong way, reporting the
device name on the guest side instead of the target name on the host side).

Fixes: f8333b3b0a ("qemu: Fix domfsinfo for non-PCI device information ...")
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1858771
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>