ALSA: hda - More description about patch module option

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 012858d..414700b 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -749,6 +749,10 @@
     bdl_pos_adj	- Specifies the DMA IRQ timing delay in samples.
 		Passing -1 will make the driver to choose the appropriate
 		value based on the controller chip.
+    patch	- Specifies the early "patch" files to modify the HD-audio
+    		setup before initializing the codecs.  This option is
+		available only when CONFIG_SND_HDA_PATCH_LOADER=y is set.
+		See HD-Audio.txt for details.
     
     [Single (global) options]
     single_cmd  - Use single immediate commands to communicate with