Implement ethtool_ops get_wol and set_wol.
Implement Wake-on-LAN support.

Wol requires hardware board support which use sub id
to identify.
Magic packets are checked by fw, for now just support
WAKE_MAGIC.
Signed-off-by: Mengyuan Lou <mengyuanlou@net-swift.com>
Signed-off-by: David S. Miller <davem@davemloft.net>