the call to pci_configure_bus(9) and it's supporting code is
copied verbatim from the prep port.
this allows us to completely remove the really gross pegasos
specific pegasospci_indirect_attach_hook() that set various
pci command regs, since all those devices (mostly work now,
see below) and additionally PCI plugin cards work now too.
it also makes the pegasos onboard vr(4) ethernet work with
disk boot (it previously only worked with netboot.)
in the generic macppc ofw pci conf hook and for pegasos,
don't configure the viaide(4) device, and don't configure
memory space on the fwohci(4) device.
with this, and my other recent ofppc/ppc changes the pegasos
port is mostly functional. the marvell gige is not working,
and my 512mb appears as only about 256mb, but otherwise
this port is almost done!
626bd12a5c