ASoC: ti: sdma-pcm: Add back the flags parameter for non standard dma names

ASoC: ti: sdma-pcm: Add back the flags parameter for non standard dma names

When non standard names are used it is possible that one of the directions
are not provided, thus the flags needs to be present to tell the core that
we have half duplex setup.

Fixes: af41d73169ef ("ASoC: ti: remove compat dma probing")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191028115207.5142-1-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>