ASoC: imx-mc13783: Add audmux settings for mx27pdk

mx27pdk board also has a mc13783 codec.

Add support for it and do a run-time machine type check to perform the correct
audiomux settings.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>