From Jason Cooper:
mvebu msi pci changes for v3.12

 - introduce support for MSI on PCI
 - fix s390 build breakage when !HAVE_GENERIC_HARDIRQS

NOTE: This branch is a dependency for changes going though arm-soc from both
Thomas Petazzoni and Thierry Reding.

* tag 'msi-3.12' of git://git.infradead.org/linux-mvebu:
  PCI: msi: add default MSI operations for !HAVE_GENERIC_HARDIRQS platforms
  ARM: pci: add ->add_bus() and ->remove_bus() hooks to hw_pci
  of: pci: add registry of MSI chips
  PCI: Introduce new MSI chip infrastructure
  PCI: remove ARCH_SUPPORTS_MSI kconfig option
  PCI: use weak functions for MSI arch-specific functions
Signed-off-by: Olof Johansson <olof@lixom.net>