[ALSA] Add description for ALC260 codec

Modules: Documentation

Added description for ALC260 codec models in hda-intel driver section.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Documentation/sound/alsa/ALSA-Configuration.txt

@@ -663,6 +663,10 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
 			adjusted.  Appearing only when compiled with
 			$CONFIG_SND_DEBUG=y
 
+	ALC260
+	  hp		HP machines
+	  fujitsu	Fujitsu S7020
+
 	CMI9880
 	  minimal	3-jack in back
 	  min_fp	3-jack in back, 2-jack in front