x86/PCI: Fix PCI config space for domains > 0

John Keller reports that PCI config space access is broken on machines
with more than one domain.  conf1 accesses only work for domain 0, so make sure
we check the domain number in the raw routines before trying conf1.

Reported-by: John Keller <jpk@sgi.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>