ALSA: wss_lib: rename cs4231.h into wss.h

Rename file include/sound/cs4231.h
into include/sound/wss.h

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Reviewed-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>