virtio, pci fixes, enhancements

Almost exclusively bugfixes, though in this case,
we are adding functionality to the pxb in order
to make OVMF work on it.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Fri Jun 26 14:43:27 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:
  Fix glib_subprocess test
  hw/pci-bridge: format special OFW unit address for PXB host
  hw/core: explicit OFW unit address callback for SysBusDeviceClass
  hw/pci-bridge: disable SHPC in PXB
  hw/pci-bridge: introduce "shpc" property
  hw/pci: introduce shpc_present() helper function
  hw/pci-bridge: add macro for "msi" property
  hw/pci-bridge: add macro for "chassis_nr" property
  hw/pci-bridge: expose _test parameter in SHPC_VMSTATE()
  migration: introduce VMSTATE_BUFFER_UNSAFE_INFO_TEST()
  add pci-bridge-seat
  pc: cleanup and convert TMP ACPI device description to AML API
  MAINTAINERS: add ACPI entry
  vhost: correctly pass error to caller in vhost_dev_enable_notifiers()
  balloon: add a feature bit to let Guest OS deflate balloon on oom
  qdev: fix OVERFLOW_BEFORE_WIDEN
  virito-pci: fix OVERRUN problem
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>