ASoC: ti: davinci-mcasp: Fix DIT mode support

ASoC: ti: davinci-mcasp: Fix DIT mode support

The DIT mode support has not been tested due to lack of platform where it
can be tested.
To be able to use the McASP on OMAP4/5 (only supporting DIT mode) we need
to have DIT mode working in the McASP driver on a know platform.
After hacking around (on BBW, mcasp1.axr1 can be routed out for this) it
appeared that DIT mode is broken.

This patch fixes it up and 16/24 bit audio works along with passthrough,
but I have only tested with DTS example and test files.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210705194249.2385-2-peter.ujfalusi@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>