MFD: twl4030: add twl4030_codec MFD as a new child to the core

New MFD child to twl4030 MFD device.

Reason for the twl4030_codec MFD: the vibra control is actually in the codec
part of the twl4030. If both the vibra and the audio functionality is needed
from the twl4030 at the same time, than they need to control the codec power
and APLL at the same time without breaking the other driver.
Also these two has to be able to work without the need for the other driver.

This MFD device will be used by the drivers, which needs resources
from the twl4030 codec like audio and vibra.

The platform specific configuration data is passed along to the
child drivers (audio, vibra).

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>