[ALSA] Add description of aw2 driver

Added a brief description of aw2 driver to ALSA-Configuration.txt.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 2cfb8b4..8a645a4 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -284,6 +284,13 @@
            control correctly. If you have problems regarding this, try
            another ALSA compliant mixer (alsamixer works).
 
+  Module snd-aw2
+  --------------
+
+    Module for Audiowerk2 sound card
+
+    This module supports multiple cards.
+
   Module snd-azt2320
   ------------------