arm64: dts: renesas: r9a07g044: Add RSPI{0,1,2} nodes

Add RSPI{0,1,2} nodes to R9A07G044 (RZ/G2L) 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/20211117011247.27621-2-prabhakar.mahadev-lad.rj@bp.renesas.com


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