media: v4l: omap_vout: vrfb: Convert to dmaengine

The dmaengine driver for sDMA now have support for interleaved transfer.
This trasnfer type was open coded with the legacy omap-dma API, but now
we can move it to dmaengine.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>