Merge remote-tracking branch 'remotes/mcayland/tags/qemu-openbios-signed' into staging

Update OpenBIOS images

# gpg: Signature made Mon 18 Apr 2016 09:39:31 BST using RSA key ID AE0F321F
# gpg: Good signature from "Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>"

* remotes/mcayland/tags/qemu-openbios-signed:
  Update OpenBIOS images
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

openbios @ 422b9166

-Subproject commit 0dbda5d935f95391d16431cd3c079fbf53d668df
+Subproject commit 422b916649aa0db8c5edadccb22387b3e807e3b2