ASoC: core: Move the default regmap I/O setting to snd_soc_register_codec()

Add the default regmap I/O setting to snd_soc_register_codec() while
the CODEC is initialising, which will be called by CODEC driver device
probe(), and then we can make XXX_set_cache_io() go away entirely from each
CODEC ASoC probe.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 0b83168..2f62436 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -754,6 +754,7 @@
 		unsigned int freq_in, unsigned int freq_out);
 
 	/* codec IO */
+	struct regmap *(*get_regmap)(struct device *);
 	unsigned int (*read)(struct snd_soc_codec *, unsigned int);
 	int (*write)(struct snd_soc_codec *, unsigned int, unsigned int);
 	int (*display_register)(struct snd_soc_codec *, char *,