qeth: Drop ARP packages on HiperSockets interface with NOARP attribute.

A network interface can get ARP packets even when the interface has
NOARP specified. In a HiperSockets environment this disturbs receiving
systems when packets are sent on the multicast queue. (E.g. TCP/IP on
z/VM issues messages reporting invalid data on the HiperSockets
interface.)
Qeth will no longer send ARP packets on HiperSockets interface when
interface has the NOARP attribute.

Signed-off-by: Klaus D. Wacker <kdwacker@de.ibm.com>
Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>