ARM: dts: exynos: No need to enable TMU nodes on Odroid XU3 family

The thermal nodes are not disabled in exynos5420.dtsi so there is no
need to manually enable them on Odroid XU3/XU3-Lite/XU4 boards.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>