s390/qeth: do early device setup for z/VM IQD NICs

qeth currently supports early setup for OSM and OSN devices.
This patch adds early setup support for z/VM HiperSockets,
since they can only be coupled to L3 networks.

Based on an initial version by Dmitriy Lakhvich.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>