ARM: dts: exynos: Enable GPU/Mali T604 on Chromebook Snow

Tested with kmscube and some glmark2* tests on Chromebook snow.
Frequency adapts with load.
Signed-off-by: Guillaume Gardet <guillaume.gardet@arm.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/boot/dts/exynos5250-snow-common.dtsi

@@ -529,6 +529,11 @@ &i2s0 {
 	status = "okay";
 };
 
+&mali {
+	mali-supply = <&buck4_reg>;
+	status = "okay";
+};
+
 &mixer {
 	status = "okay";
 };