I'm don't think all of this code should move.
In particular, parts of prom_parse.c dealing with irqs handle virtual
irqs in a powerpc specific way.
I also think ifdef PPC_PSERIES and PPC_64 and PPC_32 in prom.c are
indicative of the fact that alot of this is dealing with
Probably some parts of these files, but it's going to take some tweezing
to figure out what parts.