ALSA: opti93x: use cs4231 lib

This patch converts the Opti93x driver to use
the cs4231 library instead of duplicating the code.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Tested-by: NRene Herman <rene.herman@gmail.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>

sound/isa/Kconfig

@@ -304,7 +304,7 @@ config SND_OPTI93X
 	tristate "OPTi 82C93x"
 	select SND_OPL3_LIB
 	select SND_MPU401_UART
-	select SND_PCM
+	select SND_CS4231_LIB
 	help
 	  Say Y here to include support for soundcards based on Opti
 	  82C93x chips.