ARM: dts: imx: use dual-fifo sdma script for ssi

Use dual-fifo sdma scripts instead of shared scripts for ssi on i.MX series.

Signed-off-by: Nicolin Chen <b42378@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>