[ALSA] hda-codec - Add missing descriptions for STAC codec models

Added the missing descriptions for STAC codec models.

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 8a645a4..999b704 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -1030,6 +1030,16 @@
 	  3stack	D965 3stack
 	  5stack	D965 5stack + SPDIF
 	  dell-3stack	Dell Dimension E520
+	  dell-bios	Fixes with Dell BIOS setup
+
+	STAC92HD71B*
+	  ref		Reference board
+	  dell-m4-1	Dell desktops
+	  dell-m4-2	Dell desktops
+
+	STAC92HD73*
+	  ref		Reference board
+	  dell-m6	Dell desktops
 
 	STAC9872
 	  vaio		Setup for VAIO FE550G/SZ110