dmaengine: imx-sdma: Add a new DMATYPE for Shared Peripheral ASRC

Shared Peripheral ASRC, running on SPBA, needs to use shp sciprts for
DMA transfer. So this patch just adds a new DMATYPE for it.

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