MFD: DaVinci Voice Codec

This is the MFD driver for the DaVinci Voice codec, it has two clients:

* Voice codec interface
* Voice codec CQ93VC

Signed-off-by: Miguel Aguilar <miguel.aguilar@ridgerun.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>