ASoC: Few constifications (mostly arguments)

Merge series from Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>:

Make few pointers in ASoC functions as pointers to const, so the code is
clearer to read, a bit safer and allows further constifications (e.g.
placing some data as rodata).

diff --cc include/sound/soc-dai.h
Simple merge

diff --cc sound/soc/codecs/wcd9335.c
Simple merge

diff --cc sound/soc/codecs/wcd934x.c
Simple merge

diff --cc sound/soc/soc-utils.c
Simple merge