arm64: dts: renesas: r9a09g056n48-rzv2n-evk: Fix pinctrl node name for GBETH1

arm64: dts: renesas: r9a09g056n48-rzv2n-evk: Fix pinctrl node name for GBETH1

Rename the GBETH1 pinctrl node from "eth0" to "eth1" to avoid duplicate
node names in the DT and correctly reflect the label "eth1_pins".

Fixes: f111192baa80 ("arm64: dts: renesas: r9a09g056n48-rzv2n-evk: Enable GBETH")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20250703235544.715433-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>