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/wm8940.c b/sound/soc/codecs/wm8940.c
index 2cb16f8..23086e2 100644
--- a/sound/soc/codecs/wm8940.c
+++ b/sound/soc/codecs/wm8940.c
@@ -768,6 +768,7 @@
 
 	i2c_set_clientdata(i2c, wm8940);
 	wm8940->control_data = i2c;
+	wm8940->control_type = SND_SOC_I2C;
 
 	ret = snd_soc_register_codec(&i2c->dev,
 			&soc_codec_dev_wm8940, &wm8940_dai, 1);