ASoC: Use symmetric rates for WM8974

The chip has a single LRCLK.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm8974.c b/sound/soc/codecs/wm8974.c
index cb2c412..8c8fc60 100644
--- a/sound/soc/codecs/wm8974.c
+++ b/sound/soc/codecs/wm8974.c
@@ -631,6 +631,7 @@
 		.rates = WM8974_RATES,
 		.formats = WM8974_FORMATS,},
 	.ops = &wm8974_ops,
+	.symmetric_rates = 1,
 };
 EXPORT_SYMBOL_GPL(wm8974_dai);