ASoC: codecs: Remove unused reg_cache fields from device structs

The multi-component patch(commit f0fba2ad1) moved the allocation of the
register cache from the driver to the ASoC core. Most drivers where adjusted to
this, but there are quite a few drivers left which now have an unused reg_cache field in
their private device struct.
This patch removes these unused fields.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/uda1380.c

@@ -35,7 +35,6 @@
 /* codec private data */
 struct uda1380_priv {
 	struct snd_soc_codec *codec;
-	u16 reg_cache[UDA1380_CACHEREGNUM];
 	unsigned int dac_clk;
 	struct work_struct work;
 	void *control_data;