ASoC: davinci-mcasp: Format data delay configuration enhancement

Use intermediate variable for the data delay needed for the specific format
and write the register after the format configuration at once.
This will help to control the number of lines as support for more formats
going to be added.
Also fixes a case when we switch between two formats with different delay
requirements.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>