imx-drm changes to use media bus formats and LDB drm_panel support

- Add media bus formats needed by imx-drm
- Switch to use media bus formats to describe the pixel format
  on the internal parallel bus between display interface and
  encoders
- Some preparations for TV Output via TVEv2 on i.MX5
- Add drm_panel support to the i.MX LVDS driver, allow to
  determine the bus pixel format from the panel descriptor.

* tag 'imx-drm-next-2015-03-31' of git://git.pengutronix.de/git/pza/linux:
  drm/imx: imx-ldb: allow to determine bus format from the connected panel
  drm/imx: imx-ldb: reset display clock input when disabling LVDS
  drm/imx: imx-ldb: add drm_panel support
  drm/imx: consolidate bus format variable names
  drm/imx: switch to use media bus formats
  Add RGB666_1X24_CPADHI media bus format
  Add YUV8_1X24 media bus format
  Add BGR888_1X24 and GBR888_1X24 media bus formats
  Add LVDS RGB media bus formats
  Add RGB444_1X12 and RGB565_1X16 media bus formats
  drm/imx: ipuv3-crtc: Allow to divide DI clock from TVEv2
  drm/imx: Add support for interlaced scanout