ASoC: rt5640: add default case for unexpected ID

We may read an unexpected value when detemining which codec is attached.
In that case, either a unsupported codec is attached or something wrong
with I2C. The driver will not work properly on both cases. So we return
an error for that.
Signed-off-by: NBard Liao <bardliao@realtek.com>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

sound/soc/codecs/rt5640.c

@@ -2018,6 +2018,10 @@ static int rt5640_probe(struct snd_soc_codec *codec)
 			rt5639_specific_dapm_routes,
 			ARRAY_SIZE(rt5639_specific_dapm_routes));
 		break;
+	default:
+		dev_err(codec->dev,
+			"The driver is for RT5639 RT5640 or RT5642 only\n");
+		return -ENODEV;
 	}
 
 	return 0;