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

Documentation/devicetree/bindings/display/panel/mitsubishi,aa104xd12.yaml

@@ -11,13 +11,23 @@ maintainers:
   - Thierry Reding <thierry.reding@gmail.com>
 
 allOf:
-  - $ref: lvds.yaml#
+  - $ref: panel-common.yaml#
+  - $ref: /schemas/display/lvds.yaml/#
+
+select:
+  properties:
+    compatible:
+      contains:
+        const: mitsubishi,aa104xd12
+
+  required:
+    - compatible
 
 properties:
   compatible:
     items:
       - const: mitsubishi,aa104xd12
-      - {} # panel-lvds, but not listed here to avoid false select
+      - const: panel-lvds
 
   vcc-supply:
     description: Reference to the regulator powering the panel VCC pins.
@@ -39,6 +49,11 @@ additionalProperties: false
 required:
   - compatible
   - vcc-supply
+  - data-mapping
+  - width-mm
+  - height-mm
+  - panel-timing
+  - port
 
 examples:
   - |+