[ALSA] Added model for Uniwill laptop with ALC861

Added a new model 'uniwill-m31' for Uniwill laptops with ALC861
codec chip.  The patch is taken from ALSA bug#2035, and modifeid.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index d0dbc3f..74be228 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -827,6 +827,7 @@
 	  3stack-dig	3-jack with SPDIF I/O
 	  6stack-dig	6-jack with SPDIF I/O
 	  3stack-660	3-jack (for ALC660)
+	  uniwill-m31	Uniwill M31 laptop
 	  auto		auto-config reading BIOS (default)
 
 	CMI9880