[ALSA] ASoC documentation updates

This patch updates the documentation for ASoC to reflect the recent
changes in API between 0.12.x and 0.13.x
Changes:-
 o Removed all reference to old API's.
 o Removed references and examples of automatic DAI config and matching.
 o Fixed 80 char line length on some files.

Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>