ARM: tegra: add power gpio keys to DT

This adds the power gpio key to DT and enable the wakeup of the gpio key
for the device. The Seaboard and paz00 already had the power gpio key
binding and the power key of Whistler was on KBC. So these boards' device
tree didn't include in this patch.
Signed-off-by: NJoseph Lo <josephl@nvidia.com>
Signed-off-by: NStephen Warren <swarren@nvidia.com>

arch/arm/boot/dts/tegra20-harmony.dts

@@ -464,6 +464,17 @@
 		};
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		power {
+			label = "Power";
+			gpios = <&gpio 170 1>; /* gpio PV2, active low */
+			linux,code = <116>; /* KEY_POWER */
+			gpio-key,wakeup;
+		};
+	};
+
 	kbc {
 		status = "okay";
 		nvidia,debounce-delay-ms = <2>;

arch/arm/boot/dts/tegra20-trimslice.dts

@@ -343,6 +343,17 @@
 		};
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		power {
+			label = "Power";
+			gpios = <&gpio 190 1>; /* gpio PX6, active low */
+			linux,code = <116>; /* KEY_POWER */
+			gpio-key,wakeup;
+		};
+	};
+
 	poweroff {
 		compatible = "gpio-poweroff";
 		gpios = <&gpio 191 1>; /* gpio PX7, active low */

arch/arm/boot/dts/tegra20-ventana.dts

@@ -544,6 +544,17 @@
 		};
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		power {
+			label = "Power";
+			gpios = <&gpio 170 1>; /* gpio PV2, active low */
+			linux,code = <116>; /* KEY_POWER */
+			gpio-key,wakeup;
+		};
+	};
+
 	regulators {
 		compatible = "simple-bus";
 		#address-cells = <1>;