sky2: revert to access PCI config via device space

Using the hardware window into PCI config space is more reliable
and smaller/faster than using the pci_config routines. It avoids issues
with MMCONFIG etc.

Reverts: 167f53d0



Please apply for 2.6.24

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>