[ALSA] ad1816a - Add clockfreq module option

Documentation
Added clockfreq module option for the card with a different clock frequency
than 33kHz.

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 a18ecb9..5c49ba0 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -132,6 +132,7 @@
     mpu_irq	- IRQ # for MPU-401 UART (PnP setup)
     dma1	- first DMA # for AD1816A chip (PnP setup)
     dma2	- second DMA # for AD1816A chip (PnP setup)
+    clockfreq   - Clock frequency for AD1816A chip (default = 0, 33000Hz)
     
     Module supports up to 8 cards, autoprobe and PnP.