ASoC: dwc: fix support for more than two channels

There were missing break statements so everything used
TWO_CHANNEL_SUPPORT.

Also I added a return statement to silence a GCC warning:

	sound/soc/dwc/designware_i2s.c: In function ‘dw_i2s_hw_params’:
	sound/soc/dwc/designware_i2s.c:236:32: warning: ‘ch_reg’ may be
		used uninitialized in this function
		[-Wmaybe-uninitialized]
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/dwc/designware_i2s.c

@@ -210,15 +210,19 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
 	switch (config->chan_nr) {
 	case EIGHT_CHANNEL_SUPPORT:
 		ch_reg = 3;
+		break;
 	case SIX_CHANNEL_SUPPORT:
 		ch_reg = 2;
+		break;
 	case FOUR_CHANNEL_SUPPORT:
 		ch_reg = 1;
+		break;
 	case TWO_CHANNEL_SUPPORT:
 		ch_reg = 0;
 		break;
 	default:
 		dev_err(dev->dev, "channel not supported\n");
+		return -EINVAL;
 	}
 
 	i2s_disable_channels(dev, substream->stream);