sky2: Fix suspend/hibernation/shutdown regression with WOL enabled (rev. 2)

On my test box with the Asus M3A32-MVP main board there is a
regression from 2.6.26 related to suspend, hibernation and
shutdown.  Namely, if Wake-on-LAN is enabled with
'ethtool -s eth0 wol g', the box hangs solid during all of these
operations, while executing either sky2_suspend(), or
sky2_shutdown().  This patch fixes it for me.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>