[TG3]: WOL defaults

This patch enables WOL by default if out-of-box WOL is enabled in the
NVRAM.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>