Add atmel HLCDC driver.
* tag 'atmel-hlcdc-drm-3.20' of https://github.com/bbrezillon/linux-at91:
drm: add DT bindings documentation for atmel-hlcdc-dc driver
drm: add Atmel HLCDC Display Controller support
drm: panel: simple-panel: add bus format information for foxlink panel
drm: panel: simple-panel: add support for bus_format retrieval
drm: add bus_formats and num_bus_formats fields to drm_display_info