ASoC: davinci-mcasp: Harmonize the sub hw_params function names

Instead of
davinci_hw_common_param - for common, I2S/DIT mode settings
davinci_hw_dit_param - for DIT protocol configuration
davinci_hw_param - for I2S (and compatible protocols)

Use the following names:
mcasp_common_hw_param, mcasp_dit_hw_param and mcasp_i2s_hw_param.

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