arm64: dts: renesas: rzg3s-smarc: Enable PCIe

arm64: dts: renesas: rzg3s-smarc: Enable PCIe

The RZ Smarc Carrier-II board has PCIe headers mounted on it. Enable PCIe
support.

Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251119143523.977085-6-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>