dt-bindings: net: renesas,etheravb: R-Car V3U is R-Car Gen4

Despite the name, R-Car V3U is the first member of the R-Car Gen4
family.  Hence move its compatible value to the R-Car Gen4 section.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/devicetree/bindings/net/renesas,etheravb.yaml

@@ -40,9 +40,13 @@ properties:
               - renesas,etheravb-r8a77980     # R-Car V3H
               - renesas,etheravb-r8a77990     # R-Car E3
               - renesas,etheravb-r8a77995     # R-Car D3
-              - renesas,etheravb-r8a779a0     # R-Car V3U
           - const: renesas,etheravb-rcar-gen3 # R-Car Gen3 and RZ/G2
 
+      - items:
+          - enum:
+              - renesas,etheravb-r8a779a0     # R-Car V3U
+          - const: renesas,etheravb-rcar-gen4 # R-Car Gen4
+
       - items:
           - enum:
               - renesas,etheravb-r9a09g011 # RZ/V2M