Add missing categorizations for some s390x devices:
- zpci device -> misc
- 3270 -> display
- vfio-ccw -> misc

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>