ASoC: Intel: mfld-pcm: don't call trigger ops to DSP for internal streams

For internal stream i.e. BE we have don't need trigger ops as that
would be handled by DAPM for us in subsequent patches
Signed-off-by: NVinod Koul <vinod.koul@intel.com>
Signed-off-by: NSubhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

sound/soc/intel/sst-mfld-platform-pcm.c

@@ -464,6 +464,8 @@ static int sst_platform_pcm_trigger(struct snd_pcm_substream *substream,
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 
 	dev_dbg(rtd->dev, "sst_platform_pcm_trigger called\n");
+	if (substream->pcm->internal)
+		return 0;
 	stream = substream->runtime->private_data;
 	str_id = stream->stream_info.str_id;
 	switch (cmd) {