arm64: dts: renesas: Add support for M3ULCB+Kingfisher with R-Car M3e-2G

Add support for the Renesas R-Car Starter Kit Pro and Kingfisher combo
equipped with an R-Car M3e-2G SiP.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/54262b64be6d5c7a7ede3302259e9d15218d48a0.1626708063.git.geert+renesas@glider.be