net/mlx5: Add comment to mlx5_devlink_params_register()

Add comment to mlx5_devlink_params_register() functions so it is clear
that only driver init params should be registered here.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20230314054234.267365-4-saeed@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>