[ALSA] ice1712 - disable unused ADCs & DACs on DMX6fire

Modules: ICE1712 driver

Change the value written to hardware configuration register of envy24 chip
in the case of Terratec DMX6fire to restrict the active ADCs & DACs to 6.

Also add the dxr_enable module option to eventually leave the old behaviour
when user requests.

Signed-off-by: Alan Horstmann <gineera@aspect135.co.uk>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/pci/ice1712/ice1712.h b/sound/pci/ice1712/ice1712.h
index d7416a8..f9b22d4 100644
--- a/sound/pci/ice1712/ice1712.h
+++ b/sound/pci/ice1712/ice1712.h
@@ -325,6 +325,7 @@
 
 	unsigned int pro_volumes[20];
 	unsigned int omni: 1;		/* Delta Omni I/O */
+	unsigned int dxr_enable: 1;	/* Terratec DXR enable for DMX6FIRE */
 	unsigned int vt1724: 1;
 	unsigned int vt1720: 1;
 	unsigned int has_spdif: 1;	/* VT1720/4 - has SPDIF I/O */