- On amd64, just assume type #1 is always used. PCI 2.0 mandated
deprecated type #2 and required type #1 for all future bridges which
was well before amd64 existed.
- For i386, ignore whatever value was in 0xcf8 before testing for type #1
and instead rely on the other tests to determine if type #1 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
98bbce55fa