The net_device have some members (num_rx_queues + real_num_rx_queues)
and data-area (dev->_rx with struct netdev_rx_queue's) that were
primarily used for exporting information about RPS (CONFIG_RPS) queues
to sysfs (CONFIG_SYSFS).
For generic XDP extend struct netdev_rx_queue with the xdp_rxq_info,
and remove some of the CONFIG_SYSFS ifdefs.