[IA64] pcibus_to_node implementation for IA64

pcibus_to_node provides a way for the Linux kernel to identify to which
node a certain pcibus connects to. Allocations of control structures
for devices can then be made on the node where the pci bus is located
to allow local access during interrupt and other device manipulation.

This patch provides a new "node" field in the the pci_controller
structure. The node field will be set based on ACPI information (thanks
to Alex Williamson  <alex.williamson@hp.com for that piece).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>