net: fix xdp_rxq_info build issue when CONFIG_SYSFS is not set

The commit e817f856 ("xdp: generic XDP handling of xdp_rxq_info")
removed some ifdef CONFIG_SYSFS in net/core/dev.c, but forgot to
remove the corresponding ifdef's in include/linux/netdevice.h.

Fixes: e817f856

 ("xdp: generic XDP handling of xdp_rxq_info")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>