[ALSA] Add snd-als300 driver for Avance Logic ALS300/ALS300+ soundcards

Added snd-als300 driver for Avance Logic ALS300/ALS300+ soundcards
by Ash Willis.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Documentation/sound/alsa/ALSA-Configuration.txt

@@ -190,6 +190,15 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
 
     The power-management is supported.
 
+  Module snd-als300
+  -----------------
+
+    Module for  Avance Logic ALS300 and ALS300+
+
+    This module supports multiple cards.
+
+    The power-management is supported.
+
   Module snd-als4000
   ------------------