drm/vc4: hdmi: Add Broadcast RGB property to allow override of RGB range

Copy Intel's "Broadcast RGB" property semantics to add manual override
of the HDMI pixel range for monitors that don't abide by the content
of the AVI Infoframe.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
Link: https://lore.kernel.org/r/20221207-rpi-hdmi-improvements-v3-3-bdd54f66884e@cerno.tech


Signed-off-by: Maxime Ripard <maxime@cerno.tech>