Merge remote-tracking branch 'remotes/borntraeger/tags/s390x-20151006' into staging

Merge remote-tracking branch 'remotes/borntraeger/tags/s390x-20151006' into staging

s390: fixes

Some fixes all over the place:
- ccw bios and gcc 5.1 (avoid floating point ops)
- properly print vector registers
- sclp and sclp-event-facility no longer hang on object_unref(object_new(T))
- better name for io_subsystem_reset

One feature
- the gdb server now exposes several virtualization specific register

# gpg: Signature made Tue 06 Oct 2015 11:20:24 BST using RSA key ID B5A61C7C
# gpg: Good signature from "Christian Borntraeger (IBM) <borntraeger@de.ibm.com>"

* remotes/borntraeger/tags/s390x-20151006:
  s390x: rename io_subsystem_reset -> subsystem_reset
  s390x/info registers: print vector registers properly
  s390x: set missing parent for hotplug and quiesce events
  s390x/gdb: expose virtualization specific registers
  pc-bios/s390-ccw: avoid floating point operations

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>