The SIU ALSA driver is not using the DMA device pointer for DMA channel
filtering any more, it can be now removed.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>