Driver: add driver_add_kobj for looney iseries_veth driver

The iseries driver wants to hang kobjects off of its driver, so, to
preserve backwards compatibility, we need to add a call to the driver
core to allow future changes to work properly.

Hopefully no one uses this function in the future and the iseries_veth
driver authors come to their senses so I can remove this hack...

Cc: Dave Larson <larson1@us.ibm.com>
Cc: Santiago Leon <santil@us.ibm.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>