arm64: tegra: Add gpio-keys nodes for Darcy

Add gpio-keys nodes for the power button.
Signed-off-by: Mark Zhang <markz@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm64/boot/dts/nvidia/tegra210-p2894.dtsi

 // SPDX-License-Identifier: GPL-2.0
 
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/input/gpio-keys.h>
 #include "tegra210.dtsi"
 
 / {
@@ -52,6 +54,20 @@ clk32k_in: clock@0 {
 		};
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+		status = "okay";
+
+		power {
+			debounce-interval = <30>;
+			gpios = <&gpio TEGRA_GPIO(X, 7) GPIO_ACTIVE_LOW>;
+			label = "Power";
+			linux,code = <KEY_POWER>;
+			wakeup-event-action = <EV_ACT_ASSERTED>;
+			wakeup-source;
+		};
+	};
+
 	cpus {
 		cpu@0 {
 			enable-method = "psci";