Merged from 2a17c1bb

The SDMA driver doesn't support DMA_PAUSE and DMA_RESUME commands.
So this patch use TRIGGER_START for TRIGGER_RESUME and TRIGGER_SUSPEND
for TRIGGER_STOP as a work around so that Audio can normally stop
and restart its corresponding DMA channels.
Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>