Adds LVDS decoder, HDMI encoder and connector for the Draak board.

The LVDS0 and LVDS1 encoders can use the DU_DOTCLKIN0, DU_DOTCLKIN1 and
EXTAL externals clocks. Two of them are provided to the SoC on the Draak
board, hook them up in DT.
Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>