dmaengine: edma: re-initialize dummy slot during system resume

The last param set in a transfer should always be pointing to dummy
param set in non-cyclic mode. When system wakes from low power state
EDMA PARAM slots may be reset to random values. Hence, re-initialize
dummy slot to dummy param set on system resume.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>