acpi,pc,pci fixes and enhancements

Most changes here are hotplug related:

This merges hotplug infrastructure changes by Igor,
some acpi related fixes, and PC fixes.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Mon 10 Feb 2014 09:13:26 GMT using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream:
  ACPI: Remove commented-out code from HPET._CRS
  hw/pci: switch to a generic hotplug handling for PCIDevice
  pci/pcie: convert PCIE hotplug to use hotplug-handler API
  pci/shpc: convert SHPC hotplug to use hotplug-handler API
  acpi/piix4pm: convert ACPI PCI hotplug to use hotplug-handler API
  qdev:pci: refactor PCIDevice to use generic "hotpluggable" property
  hw/acpi: move typeinfo to the file end
  qdev: add "hotpluggable" property to Device
  qdev: add to BusState "hotplug-handler" link
  define hotplug interface
  loader: document that errno is set
  pc.c: better error message on initrd sizing failure
  pc_piix: enable legacy hotplug for Xen
  qtest: don't report signals if qtest driver enabled
  hw:piix4:acpi: reuse pcihp code for legacy PCI hotplug
  pcihp: remove unused AcpiPciHpPciStatus.device_present field
  pcihp: make pci_read() mmio calback compatible with legacy ACPI hotplug
  pcihp: make PCI hotplug mmio handlers indifferent to PCI_HOTPLUG_ADDR
  pcihp: replace enable|disable_device() with oneliners
  pcihp: reduce number of device check events

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