net: ethernet: ti: netcp_ethss: fix build

Fix reported build fail:
ERROR: "cpsw_ale_flush_multicast" [drivers/net/ethernet/ti/keystone_netcp_ethss.ko] undefined!
ERROR: "cpsw_ale_create" [drivers/net/ethernet/ti/keystone_netcp_ethss.ko] undefined!
ERROR: "cpsw_ale_add_vlan" [drivers/net/ethernet/ti/keystone_netcp_ethss.ko] undefined!

Fixes: 16f54164

 ("net: ethernet: ti: cpsw: drop CONFIG_TI_CPSW_ALE config option")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>