Some devices work (an, wdc), while others do not (ne, wi).
However, the bus is useful enough that it makes sense to go ahead and
enable it. Maybe other folks can help me debug the rest of the problems.
I'm not enabling it in the configuration file yet. (I have an uncommitted
version of the config file that I will happily share with anyone who wants to
help test or debug.)
PCI idsel and irq routing (later).
Various cleanup/rototilling to remove hardcoded pb1000 references.
Reviewed by simonb@, and derived from changes reviewed by matt@ and tsutsui@