dt-bindings: display: bridge: thc63lvd1024: Document dual-link operation

The THC63LVD1024 LVDS decoder can operate in two modes, single-link or
dual-link. In dual-link mode both input ports are used to carry even-
and odd-numbered pixels separately. Document this in the DT bindings,
along with the related rules governing port and usage.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.txt

@@ -28,6 +28,12 @@ Optional video port nodes:
 - port@1: Second LVDS input port
 - port@3: Second digital CMOS/TTL parallel output
 
+The device can operate in single-link mode or dual-link mode. In single-link
+mode, all pixels are received on port@0, and port@1 shall not contain any
+endpoint. In dual-link mode, even-numbered pixels are received on port@0 and
+odd-numbered pixels on port@1, and both port@0 and port@1 shall contain
+endpoints.
+
 Example:
 --------