Altix: ACPI SSDT PCI device support

Add SN platform support for running with an ACPI
capable PROM that defines PCI devices in SSDT
tables. There is a SSDT table for every occupied
slot on a root bus, containing info for every
PPB and/or device on the bus. The SSDTs will be
dynamically loaded/unloaded at hotplug enable/disable.

Platform specific information that is currently
passed via a SAL call, will now be passed via the
Vendor resource in the ACPI Device object(s) defined
in each SSDT.

Signed-off-by: John Keller <jpk@sgi.com>
Cc: Greg KH <greg@kroah.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>