[ALSA] Add missing model for HD-audio Cx5045 codec

Added the description of the model fujitsu for Cx5045 codec chip.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>

Documentation/sound/alsa/ALSA-Configuration.txt

@@ -946,6 +946,7 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
 	
 	Conexant 5045
 	  laptop	Laptop config 
+	  fujitsu	Fujitsu Si1520 laptop
 	  test		for testing/debugging purpose, almost all controls
 			can be adjusted.  Appearing only when compiled with
 			$CONFIG_SND_DEBUG=y