arm64: tegra: Add GPU power rail regulator on Smaug

Add the GPU power rail regulator node for the Pixel C.
Signed-off-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm64/boot/dts/nvidia/tegra210-smaug.dts

@@ -1370,11 +1370,27 @@ max77621_cpu: max77621@1b {
 			maxim,dvs-default-state = <1>;
 			maxim,enable-active-discharge;
 			maxim,enable-bias-control;
-			maxim,enable-etr;
 			maxim,enable-gpio = <&pmic 5 0>;
 			maxim,externally-enable;
 		};
 
+		max77621_gpu: regulator@1c {
+			compatible = "maxim,max77621";
+			reg = <0x1c>;
+			interrupt-parent = <&gpio>;
+			interrupts = <TEGRA_GPIO(A, 6) IRQ_TYPE_LEVEL_LOW>;
+			regulator-min-microvolt = <840000>;
+			regulator-max-microvolt = <1150000>;
+			regulator-name = "PPVAR_GPU";
+			regulator-ramp-delay = <12500>;
+			maxim,dvs-default-state = <1>;
+			maxim,enable-active-discharge;
+			maxim,enable-bias-control;
+			maxim,disable-etr;
+			maxim,enable-gpio = <&pmic 6 GPIO_ACTIVE_HIGH>;
+			maxim,externally-enable;
+		};
+
 		pmic: pmic@3c {
 			compatible = "maxim,max77620";
 			reg = <0x3c>;