ASoC: codecs: Add missing control_type initialization

Some codec drivers do not initialize the control_type field in their private
device struct, but still use it when calling snd_soc_codec_set_cache_io.
This patch fixes the issue by properly initializing it in the drivers probe
functions.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org (for 2.6.37 only)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 21986c4..ff6ff2f 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -1013,6 +1013,7 @@
 		return -ENOMEM;
 
 	i2c_set_clientdata(i2c, wm8960);
+	wm8960->control_type = SND_SOC_I2C;
 	wm8960->control_data = i2c;
 
 	ret = snd_soc_register_codec(&i2c->dev,