arm64: dts: renesas: Add Renesas R8A779M1 SoC support

Add support for the Renesas R-Car H3e-2G (R8A779M1) SoC, which is a
different grading of the R-Car H3 ES3.0 (R8A77951) SoC.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/ec2196d1b6b142955007e48124eb59ec4e0cee5f.1626708063.git.geert+renesas@glider.be