arm64: dts: renesas: r8a7799[05]: Point LVDS0 to its companion LVDS1

Add the new renesas,companion property to the LVDS0 node to point to the
companion LVDS encoder LVDS1.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a77990.dtsi

@@ -1803,6 +1803,8 @@ lvds0: lvds-encoder@feb90000 {
 			resets = <&cpg 727>;
 			status = "disabled";
 
+			renesas,companion = <&lvds1>;
+
 			ports {
 				#address-cells = <1>;
 				#size-cells = <0>;

arch/arm64/boot/dts/renesas/r8a77995.dtsi

@@ -1038,6 +1038,8 @@ lvds0: lvds-encoder@feb90000 {
 			resets = <&cpg 727>;
 			status = "disabled";
 
+			renesas,companion = <&lvds1>;
+
 			ports {
 				#address-cells = <1>;
 				#size-cells = <0>;