net/mlx5e: CT: Fix insert rules when TC_CT config isn't enabled

If CONFIG_MLX5_TC_CT isn't enabled, all offloading of eswitch tc rules
fails on parsing ct match, even if there is no ct match.

Return success if there is no ct match, regardless of config.

Fixes: 4c3844d9 ("net/mlx5e: CT: Introduce connection tracking")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>