[ros-svn] [hbirr] 18494: - Do only read the pci config header. Some devices/drivers don't like it

[hbirr at svn.reactos.com]

- Do only read the pci config header. Some devices/drivers don't like it 
  if the complete pci config space is accessed (like my Tekram DC-390F SCSI controller).  
- Replaced some numeric values with nice named constants.




Updated files:
trunk/reactos/drivers/bus/pci/pdo.c