dt-bindings: thermal: rcar: Add device tree support for r8a7743

Add thermal sensor support for r8a7743 SoC. The Renesas RZ/G1M
(r8a7743) thermal sensor module is identical to the R-Car Gen2 family.

No driver change is needed due to the fallback compatible value
"renesas,rcar-gen2-thermal".

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>