ASoC: omap-twl4030: Simple machine driver for TI SoC with twl4030 codec

Machine driver to handle simple devices using twl4030 as audio codec.
The driver supports the following boards:
- Beagleboard or Devkit8000
- Gumstix Overo or CompuLab CM-T35/CM-T3730
- IGEP v2
- OMAP3EVM

All of these boards can be switched to use this driver since their setup is
identical.
Devicetree support for the omap-twl4030 machine driver also implemented.

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