dt-bindings: thermal: samsung: Convert to dtschema

Convert the Samsung Exynos SoC Thermal Management Unit bindings to DT
schema format.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220122132554.65192-2-krzysztof.kozlowski@canonical.com


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