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>