i386 and x86-64 pci mmconfig code have a lot in common.  So share what's
shareable between the two.
Signed-off-by: NOlivier Galibert <galibert@pobox.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>