ASoC: max98090: Remove unused control_data field

The driver assigns a value to the control_data field of the driver's state
struct, but never reads it again. Which means it is unused and can be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/max98090.c

@@ -2350,7 +2350,6 @@ static int max98090_i2c_probe(struct i2c_client *i2c,
 
 	max98090->devtype = id->driver_data;
 	i2c_set_clientdata(i2c, max98090);
-	max98090->control_data = i2c;
 	max98090->pdata = i2c->dev.platform_data;
 	max98090->irq = i2c->irq;
 

sound/soc/codecs/max98090.h

@@ -1523,7 +1523,6 @@ struct max98090_priv {
 	struct regmap *regmap;
 	struct snd_soc_codec *codec;
 	enum max98090_type devtype;
-	void *control_data;
 	struct max98090_pdata *pdata;
 	unsigned int sysclk;
 	unsigned int bclk;