Rings in RING mode should be using the DMA device for DMA API as in this
mode the ringacc will not access the ring memory in any ways, but the DMA
is.

Fix up the ring configuration and set the dma_dev unconditionally and let
the ringacc driver to select the correct device to use for DMA API.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Link: https://lore.kernel.org/r/20201208090440.31792-7-peter.ujfalusi@ti.comSigned-off-by: Vinod Koul <vkoul@kernel.org>