e1000e: add new wakeup cababilities

Ethtool supports wake-on-ARP and wake-on-link, and so does the hardware
supported by e1000e.  This patch just introduces the two.

Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>