ASoC: rsnd: try to connect connected mod is not error

If system uses CTU/MUX, CTU/MUX/DVC will try to connect same CMD to
system, but it is not error in this case.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>