qeth: support z/VM VSWITCH Port Isolation

qeth: support z/VM VSWITCH Port Isolation

z/VM Virtual Switch Port Isolation allows guests on a VLAN UNAWARE
virtual switch to be isolated from other guests on the VSWITCH.
(See z/VM Apars VM64281 and VM64463).
The Linux qeth driver is affected, because it has to handle new
error codes introduced with the z/VM VSWITCH Port Isolation support.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>