arm64: dts: exynos: Add GPU/Mali T760 node to Exynos7

Add nodes for GPU (Mali T760) to Exynos7.  Current support for Exynos7
misses a lot, including proper clocks, power domains, frequency and
voltage scaling and cooling.  However this still can provide basic GPU
description.  Not tested on HW.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm64/boot/dts/exynos/exynos7-espresso.dts

@@ -59,6 +59,11 @@ &fin_pll {
 	clock-frequency = <24000000>;
 };
 
+&gpu {
+	mali-supply = <&buck6_reg>;
+	status = "okay";
+};
+
 &serial_2 {
 	status = "okay";
 };

arch/arm64/boot/dts/exynos/exynos7.dtsi

@@ -78,6 +78,17 @@ cpu_atlas3: cpu@3 {
 		};
 	};
 
+	gpu: gpu@14ac0000 {
+		compatible = "samsung,exynos5433-mali", "arm,mali-t760";
+		reg = <0x14ac0000 0x5000>;
+		interrupts = <GIC_SPI 241 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 242 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 240 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "job", "mmu", "gpu";
+		status = "disabled";
+		/* TODO: operating points for DVFS, cooling device */
+	};
+
 	psci {
 		compatible = "arm,psci-0.2";
 		method = "smc";