ASoC: davinci-mcasp: Support for McASP version found in DRA7xx

ASoC: davinci-mcasp: Support for McASP version found in DRA7xx

The IP in DRA7xx is similar to the IP found in TI81xxAM3xxx/AM4xxx type of
SoCs but it is is integrated with sDMA instead of eDMA. The suitable pcm
driver for DRA7xx is the omap-pcm driver which is using dmaengine.
In the driver we can configure both dma related structures used for eDMA and
sDMA. The only thing we need to make sure that we set the correct dma_data
at startup with snd_soc_dai_set_dma_data()

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