This commit adds compatibles used in H6 display pipeline, namely for
display engine, mixer and TV TCON.

H6 display engine is somewhat similar to R40, just less TCONs and
mixer support more features.
Reviewed-by: NRob Herring <robh@kernel.org>
Reviewed-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NJernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: NMaxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181104182705.18047-8-jernej.skrabec@siol.net