ARM: tegra: Enable power key on Venice2

Contrary to the rest of the keyboard, which is connected to the ChromeOS
embedded controller, the power key is hooked up to a GPIO. Add a device
tree node to handle it.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

arch/arm/boot/dts/tegra124-venice2.dts

@@ -954,6 +954,18 @@ clk32k_in: clock@0 {
 		};
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		power {
+			label = "Power";
+			gpios = <&gpio TEGRA_GPIO(Q, 0) GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_POWER>;
+			debounce-interval = <10>;
+			gpio-key,wakeup;
+		};
+	};
+
 	regulators {
 		compatible = "simple-bus";
 		#address-cells = <1>;