ASoC: wm8904: correct the index

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm8904.c b/sound/soc/codecs/wm8904.c
index 0013afe..dc4262e 100644
--- a/sound/soc/codecs/wm8904.c
+++ b/sound/soc/codecs/wm8904.c
@@ -100,7 +100,7 @@
 	{ 14,  0x0000 },     /* R14  - Power Management 2 */
 	{ 15,  0x0000 },     /* R15  - Power Management 3 */
 	{ 18,  0x0000 },     /* R18  - Power Management 6 */
-	{ 19,  0x945E },     /* R20  - Clock Rates 0 */
+	{ 20,  0x945E },     /* R20  - Clock Rates 0 */
 	{ 21,  0x0C05 },     /* R21  - Clock Rates 1 */
 	{ 22,  0x0006 },     /* R22  - Clock Rates 2 */
 	{ 24,  0x0050 },     /* R24  - Audio Interface 0 */