RDMA/drivers: Convert easy drivers to use ib_device_set_netdev()

Drivers that never change their ndev dynamically do not need to use
the get_netdev callback.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Acked-by: Michal Kalderon <michal.kalderon@marvell.com>
Acked-by: Adit Ranadive <aditr@vmware.com>