[ALSA] Add description about a new option of nm256 driver

Modules: Documentation

Add description about a new option of nm256 driver.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Documentation/sound/alsa/ALSA-Configuration.txt

@@ -954,6 +954,8 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
     use_cache        - 0 or 1 (disabled by default)
     vaio_hack        - alias buffer_top=0x25a800
     reset_workaround - enable AC97 RESET workaround for some laptops
+    reset_workaround2 - enable extended AC97 RESET workaround for some
+		      other laptops
 
     Module supports autoprobe and multiple chips (max 8).
 
@@ -984,6 +986,11 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
     workaround is enabled automatically.  For other laptops with a
     hard freeze, you can try reset_workaround=1 option.
 
+    Note: Dell Latitude CSx laptops have another problem regarding
+    AC97 RESET.  On these laptops, reset_workaround2 option is
+    turned on as default.  This option is worth to try if the
+    previous reset_workaround option doesn't help.
+
     Note: This driver is really crappy.  It's a porting from the
     OSS driver, which is a result of black-magic reverse engineering.
     The detection of codec will fail if the driver is loaded *after*