[ALSA] Add snd-portman2x4 driver for Midiman Portman 2x4 MIDI device

snd-portman2x4 driver supports Midiman Portman 2x4 parallel port
MIDI device.

Signed-off-by: Matthias Koenig <mkoenig@suse.de>
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 3a1bd3a..79a44f5 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -1411,6 +1411,13 @@
 
     This module supports multiple cards.
 
+  Module snd-portman2x4
+  ---------------------
+
+    Module for Midiman Portman 2x4 parallel port MIDI interface
+
+    This module supports multiple cards.
+
   Module snd-powermac (on ppc only)
   ---------------------------------