[OpenBIOS] [PATCH][v2] Really create a tree for PCI devices

[Laurent Vivier]

This patch really creates a tree for PCI devices: all PCI devices are  
leafs under the last PCI host found.
This is not the "perfect" solution, but a step in the good direction.

v2: on sparc64, as PCI probing is disabled, move forth pci definitions  
removed from common part to sparc64 directories. This part is not  
compiled & not tested.