dt-bindings: thermal: Document Renesas RZ/G2L TSU

Document the Thermal Sensor Unit(TSU) in the RZ/G2L SoC.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211130155757.17837-2-biju.das.jz@bp.renesas.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>