ARM: dts: samsung: exynos4210: enable polling

It seems that thermal in Exynos 4210 is broken without this, as it will
never decrease cooling after increasing it.

Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
Link: https://lore.kernel.org/r/20230911133417.14042-1-m.majewski2@samsung.com


[krzk: fix comment coding style and line wrapping]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>