ASoC: wm8974: fix a wrong bit definition

The wm8974 datasheet defines BUFIOEN as bit 2.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org

sound/soc/codecs/wm8974.c

@@ -47,7 +47,7 @@ static const u16 wm8974_reg[WM8974_CACHEREGNUM] = {
 };
 
 #define WM8974_POWER1_BIASEN  0x08
-#define WM8974_POWER1_BUFIOEN 0x10
+#define WM8974_POWER1_BUFIOEN 0x04
 
 struct wm8974_priv {
 	struct snd_soc_codec codec;