net/mlx5e: Make mlx5e_verify_rx_mpwqe_strides static

mlx5e_verify_rx_mpwqe_strides is only used in en/params.c, so it can be
made static and removed from en/params.h.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>