smsc95xx: add wol support for more frame types

This patch adds support for wol wakeup on unicast, broadcast,
multicast and arp frames.

The wakeup filter code isn't pretty, but it works.

Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: David S. Miller <davem@davemloft.net>