ASoC: add RT5670 CODEC driver

This patch adds a minimum support of Realtek ALC5670 codec.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --cc include/sound/rt5670.h
Simple merge

diff --cc sound/soc/codecs/Kconfig
Simple merge

diff --cc sound/soc/codecs/Makefile
Simple merge

diff --cc sound/soc/codecs/rt5670-dsp.h
Simple merge

diff --cc sound/soc/codecs/rt5670.c
Simple merge

diff --cc sound/soc/codecs/rt5670.h
Simple merge