ASoC: wm8978: enable symmetric rates

wm8978 needs .symmetric_rates = 1.
The playback/capture will be strange without this patch
when it used asymmetric rate in same time
Tested-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/wm8978.c

@@ -921,6 +921,7 @@ static struct snd_soc_dai_driver wm8978_dai = {
 		.formats = WM8978_FORMATS,
 	},
 	.ops = &wm8978_dai_ops,
+	.symmetric_rates = 1,
 };
 
 static int wm8978_suspend(struct snd_soc_codec *codec)