dt-bindings: display: move LVDS data-mapping definition to separate file

As the LVDS data-mapping property is required in multiple bindings: move
it to separate file and include instead of duplicating it.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
Link: https://lore.kernel.org/r/20230523-simplepanel_support_nondefault_datamapping-v5-1-0d7928edafab@pengutronix.de
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230523-simplepanel_support_nondefault_datamapping-v5-1-0d7928edafab@pengutronix.de

dt-bindings: display: Turn lvds.yaml into a generic schema

The lvds.yaml file so far was both defining the generic LVDS properties
(such as data-mapping) that could be used for any LVDS sink, but also
the panel-lvds binding.

That last binding was to describe LVDS panels simple enough, and had a
number of other bindings using it as a base to specialise it further.

However, this situation makes it fairly hard to extend and reuse both
the generic parts, and the panel-lvds itself.

Let's remove the panel-lvds parts and leave only the generic LVDS
properties.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220127143045.310199-1-maxime@cerno.tech