ASoC: rt5640: add master clock handling for rt5640

enable/disable master clock when codec is active or not.

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/rt5640.h b/sound/soc/codecs/rt5640.h
index 83a7150..1761c3a9 100644
--- a/sound/soc/codecs/rt5640.h
+++ b/sound/soc/codecs/rt5640.h
@@ -12,6 +12,7 @@
 #ifndef _RT5640_H
 #define _RT5640_H
 
+#include <linux/clk.h>
 #include <sound/rt5640.h>
 
 /* Info */
@@ -2097,6 +2098,7 @@
 	struct snd_soc_codec *codec;
 	struct rt5640_platform_data pdata;
 	struct regmap *regmap;
+	struct clk *mclk;
 
 	int sysclk;
 	int sysclk_src;