Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20151201' into staging

Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20151201' into staging

Last round of s390x fixes for 2.5:
- The bios should be built for the first z machine, so that newer
  instructions don't creep in.
- Silence annoying message when running make check.
- Fix a problem with the pci iommu exposed by recent changes.

# gpg: Signature made Tue 01 Dec 2015 08:59:42 GMT using RSA key ID C6F02FAF
# gpg: Good signature from "Cornelia Huck <huckc@linux.vnet.ibm.com>"
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>"

* remotes/cohuck/tags/s390x-20151201:
  s390x/pci: fix up IOMMU size
  s390x: no deprecation warning while testing
  pc-bios/s390-ccw: rebuild image
  pc-bios/s390-ccw: build for z900

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