This patch reworks the code that deals with matching PCI devices
with Open Firmware device nodes. This code made several incorrect
assumptions and can be simplified significantly. The main functional
difference now is that PHBs are no longer special cased, but that
shouldn't cause any specific problem.

It also fixes a problem where u3_iommu.c wouldn't work for PCI
devices that lacked a matching OF device node.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>