ARM: dts: exynos: drop old thermal properties from Exynos4210

The samsung,tmu_gain and samsung,tmu_reference_voltage properties of
Exynos Thermal Management Unit driver are not used since April 2018.
They were removed with commit fccfe0993b5d ("thermal: exynos: remove
parsing of samsung,tmu_gain property") and commit 61020d189dbc
("thermal: exynos: remove parsing of samsung, tmu_reference_voltage
property"), so drop them also from Exynos4210 DTS.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm/boot/dts/exynos4210.dtsi

···
 	compatible = "samsung,exynos4210-tmu";
 	clocks = <&clock CLK_TMU_APBIF>;
 	clock-names = "tmu_apbif";
-	samsung,tmu_gain = <15>;
-	samsung,tmu_reference_voltage = <7>;
 };
 
 #include "exynos4210-pinctrl.dtsi"