ASoC: sgtl5000: add one missed cache reg

Signed-off-by: Dong Aisheng <b29396@freescale.com>
Signed-off-by: Zeng Zhaoming <zhaoming.zeng@freescale.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index cf6eea8..d9f8bec 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -50,6 +50,7 @@
 	0x0000, /* 0x0016, reserved */
 	0x0000, /* 0x0018, reserved */
 	0x0000, /* 0x001A, reserved */
+	0x0000, /* 0x001C, reserved */
 	0x0000, /* 0x001E, reserved */
 	0x0000, /* 0x0020, CHIP_ANA_ADC_CTRL */
 	0x1818, /* 0x0022, CHIP_ANA_HP_CTRL */