[PATCH] x86_64: Search K8 devices on more devices.

arch/x86_64/kernel/aperture.c: The search for the AGP bridge has been
extended to search for all the 256 buses instead of the first 32. This
is required since on a some systems, the bridge may be located on a bus
much farther than the first 32. By searching all 256 buses, we guarantee
that the search succeeds on such systems.

arch/x86_64/kernel/pci-gart.c: The search for the Northbridge is not
limited to just bus 0 anymore. This is required because on certain
systems, we may not find one on bus 0.

Signed-off-by: Navin Boppuri <navin.boppuri@newisys.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>