Switch code to use the newly introduced V4L bus formats IDs instead of custom
defines. Also use the V4L encoding defines.

Some display pipelines can only provide non-RBG input pixels to the HDMI TX
Controller, this patch takes the pixel format from the plat_data if provided.
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>