mlxsw: spectrum_matchall: Pass matchall entry to sampling operations

The entry will be required by the next patches, so pass it. No
functional changes intended.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>