This fixes an issue related to the second PCI host controller working on
MPC8555/41 systems.

We track the last PCI bus number on PCI1 so that the PCI2 host
controller can properly exclude itself at the right time, exclusion
should occur after initial setup so that the early pci config cycles in
setting PCI2 actually get to the controller. 
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>