dt-bindings: net: renesas,etheravb: Document RZ/G2UL SoC

Document Gigabit Ethernet IP found on RZ/G2UL SoC. Gigabit Ethernet
Interface is identical to one found on the RZ/G2L SoC. No driver changes
are required as generic compatible string "renesas,rzg2l-gbeth" will be
used as a fallback.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -45,9 +45,10 @@ properties:
 
       - items:
           - enum:
+              - renesas,r9a07g043-gbeth # RZ/G2UL
               - renesas,r9a07g044-gbeth # RZ/G2{L,LC}
               - renesas,r9a07g054-gbeth # RZ/V2L
-          - const: renesas,rzg2l-gbeth  # RZ/{G2L,V2L} family
+          - const: renesas,rzg2l-gbeth  # RZ/{G2L,G2UL,V2L} family
 
   reg: true