ENGR00160860-2 hdmi audio driver

ENGR00160860-2 hdmi audio driver

Audio driver for i.Mx built-in HDMI Transmitter.

* Uses HDMI Transmitter's built-in DMA.
* Adds IEC958-style digital audio header info to the raw audio.
* Gets pixel clock from the IPU driver and calculates clock
  regenerator values (cts and N).
* Move ipu_id, and disp_id from the HDMI's platform data to the
  HDMI mfd's platform data. Saves them in the hdmi mfd.
* Add mfd functionality to update the clock regenerator values
  when the hdmi changes the pixel clock rate or when requested
  from the audio driver with a new audio sample rate.

Signed-off-by: Alan Tull <alan.tull@freescale.com>