ASoC: rsnd: Change stop sequece of SSI and Audio-DMA-pp.

This patch fixes the problem that DMA doesn't stop.
This patch changes order.
 old : Stop SSI. Then, stop the Audio DMAC-pp.
 new : Stop Audio DMAC-pp. Then, stop the SSI.

Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>