Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pc build fix

My last pull breaks build on systems with iasl.
Fix this up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# gpg: Signature made Mon Jun  1 20:41:08 2015 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream:
  acpi: add missing ssdt

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