net/mlx5e: Extend flower police validation

Recent net commit 4d1e07d8 ("net/mlx5e: Fix matchall police parameters
validation") removed notexceed action id validation from
mlx5e_police_validate() and left it up to callers. However, since
tc_act_can_offload_police() only exists in net-next its validation is
extended in this dedicated followup patch.

Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Jianbo Liu <jianbol@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>