[ALSA] Add descriptions for new module options of snd-sscape driver

Add descriptions for new module options of snd-sscape driver,
wss_port and dma2.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

Documentation/sound/alsa/ALSA-Configuration.txt

@@ -1706,9 +1706,11 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
     Module for ENSONIQ SoundScape PnP cards.
 
     port	- Port # (PnP setup)
+    wss_port	- WSS Port # (PnP setup)
     irq		- IRQ # (PnP setup)
     mpu_irq	- MPU-401 IRQ # (PnP setup)
     dma		- DMA # (PnP setup)
+    dma2	- 2nd DMA # (PnP setup, -1 to disable)
 
     This module supports multiple cards.  ISA PnP must be enabled.
     You need sscape_ctl tool in alsa-tools package for loading