ASoC: omap-pcm: Support for binding the platform driver to dai devices

With the new calls it is going to be possible to bind the platform driver
to a dai device which makes it easier for us in a long run to handle DT
boots, and opens the possibility to move machine driver to generic simple
card.

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