RDMA: Rename port_callback to init_port

Most provider routines are callback routines which ib core invokes.
_callback suffix doesn't convey information about when such callback is
invoked. Therefore, rename port_callback to init_port.

Additionally, store the init_port function pointer in ib_device_ops, so
that it can be accessed in subsequent patches when binding rdma device to
net namespace.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/cxgb4/provider.c

@@ -634,7 +634,7 @@ void c4iw_register_device(struct work_struct *work)
 	rdma_set_device_sysfs_group(&dev->ibdev, &c4iw_attr_group);
 	dev->ibdev.driver_id = RDMA_DRIVER_CXGB4;
 	ib_set_device_ops(&dev->ibdev, &c4iw_dev_ops);
-	ret = ib_register_device(&dev->ibdev, "cxgb4_%d", NULL);
+	ret = ib_register_device(&dev->ibdev, "cxgb4_%d");
 	if (ret)
 		goto err_kfree_iwcm;
 	return;