jhb 2a71fa9467 Adjust the code to probe for the PCI config mechanism to use.
- On amd64, just assume type  is always used.  PCI 2.0 mandated
  deprecated type  and required type  for all future bridges which
  was well before amd64 existed.
- For i386, ignore whatever value was in 0xcf8 before testing for type 
  and instead rely on the other tests to determine if type  works.  Some
  newer machines leave garbage in 0xcf8 during boot and as a result the
  kernel doesn't find PCI at all (which greatly confuses ACPI which expects
  PCI to exist when PCI busses are in the namespace).

MFC after:	3 days
Discussed with:	scottl
2007-11-28 22:20:08 +00:00
..