skge: Do not use legacy PCI power management

The skge driver used the legacy PCI power management, and did its
own PCI callbacks.  Use the same code model as Rafael's changes to
sky2. Let the PCI subsystem take care of all the PCI-specific aspects of
device handling during system power transitions.

Compile tested only (so far).

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>