dt-bindings: net: renesas-gbeth: Add support for RZ/G3E (R9A09G047) SoC

Document support for the GBETH IP found on the Renesas RZ/G3E (R9A09G047) SoC.
The GBETH block on RZ/G3E is equivalent in functionality to the GBETH found on
RZ/V2H(P) (R9A09G057).

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20250611061204.15393-1-john.madieu.xa@bp.renesas.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>