For most CODEC drivers which the REGMAP is used, the soc_probe_codec()
will do the stuff work of snd_soc_codec_set_cache_io(), which the CODEC
drivers' ASoC probe will do too, and almost at the same time.

This patch set the default I/O up try regmap, and then the CODEC drivers'
stuff work of snd_soc_codec_set_cache_io() will be redundant, while if one
CODEC driver needed to set it's own I/O, then it can rewrite the default ones.
Then could we just discard the snd_soc_codec_set_cache_io() from the CODEC
drivers' ASoC probe to simplify the code.
Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>