ASoC: rsnd: fixup rsnd_dai_call() behavior for unimplemented method

Current rsnd_dai_call didn't count callback-count if callback
wasn't implemented. Thus, it counts can be unbalance.
ex) .start : implemented
    .stop  : not implemented
This patch solve this issue

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