If skge hardware is capable of waking up the system from sleep,
enable magic packet WoL during driver initialisation.

This makes WoL work without calling 'ethtool -s ethX wol g'
for each adapter.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Tested-by: NMichael Guntsche <mike@it-loops.com>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>