Patch from Deepak Saxena

The IXP4xx PCI config cycle routines currently virtualize accesses
to device 0:0 to map to the host bridge itself. This is technically
incorrect b/c on certain boards we have an actual device wired to 0:0
and the existing code will not see these.
  

Signed-off-by: Deepak Saxena
 
Signed-off-by: Russell King