Merge remote-tracking branch 'agraf/s390-for-upstream' into staging

# By Cornelia Huck (13) and others
# Via Alexander Graf
* agraf/s390-for-upstream:
  s390: Drop set_bit usage in virtio_ccw.
  s390: css error codes.
  s390: Use s390_cpu_physical_memory_map for tpi.
  sclpconsole: Don't instantiate sclpconsole with -nodefaults
  s390: Add s390-ccw-virtio machine.
  s390-virtio: Check for NULL device in reset hypercall
  s390: Move hw files to hw/s390x
  virtio-s390: add a reset function to virtio-s390 devices
  s390: Make typeinfo const
  s390: Add new channel I/O based virtio transport.
  s390-virtio: Factor out some initialization code.
  s390: Wire up channel I/O in kvm.
  s390: Virtual channel subsystem support.
  s390: Add channel I/O instructions.
  s390: I/O interrupt and machine check injection.
  s390: Channel I/O basic definitions.
  s390: Add mapping helper functions.
  s390: Lowcore mapping helper.
  s390: Add default support for SCLP console