r8169: fix suspend/resume for down interface

The PM hooks are no-op if the r8169 interface is down (i.e. !IFF_UP).
However, as the chipset is enabled, the device will not work after a
suspend/resume cycle. The patch always issue the required PCI suspend
sequence and removes the module unload/reload workaround.

Signed-off-by: Arnaud Patard <apatard@mandriva.com>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>