This patch extends the sh dmaengine driver to support the preferred channel
selection and configuration method, instead of using the "private" field
from struct dma_chan. We add a standard filter function to be used by
slave drivers instead of implementing their own ones, and add support for
the DMA_SLAVE_CONFIG control operation, which must accompany the new
channel selection method. We still support the legacy .private channel
allocation method to cater for a smooth driver migration.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
[applied a trvial checkpath fix]
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>