The current SH DMA API is somewhat broken, not correctly matching
virtual channel to the correct SH DMAC. This wasn't noticeable when
using g2 DMA for the sound driver - one channel 0 is as good as any
other! - but caused the pvr2 driver to fail.

This patch fixes the pvr2 problem and consequently fixes the sound
driver to ensure it continues to function.

Signed-off by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>