Support for extended config space on ia64.

 - Add the new parameter 'type' to ia64_sal_pci_config_{read,write}
 - Change callers to match.
 - Don't check `value' for NULL -- drivers/pci/access.c guarantees it isn't.
 - Make pci_sal_ops static.
 - Add pci_sal_ext_ops.
 - Introduce pci_set_sal_ops() as an arch_initcall to ensure the raw_pci_ops
   get set before we walk the ACPI namespace to discover PCI root bridges