Hi Greg.  Ivan's not happy with the solution I came up with for naming
/proc/bus/pci and Anton would prefer something slightly different too,
so I abstracted the name out so each architecture can do its own thing.

This is against 2.5.72 so won't apply cleanly to your tree (it
applies to bitkeeper as of a few minutes ago with only minor offsets).
I've implemented the original name for non-PCI-domain machines; done what
ia64 and alpha need, respectively (assuming I didn't misunderstand Ivan),
and plopped in the Old Way of doing things for Sparc64, PPC and PPC64.
Maintainers may alter this to whatever degree of complexity they wish.