arm64: dts: renesas: r8a774a1: Add PCIe EP nodes

Add PCIe EP nodes to R8A774A1 (RZ/G2M) SoC dtsi.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20200814173037.17822-4-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>