ARM: dts: imx6ull-colibri: Add general wakeup key used on Colibri

This adds the possibility to wake the module with an external signal
as defined in the Colibri standard

Signed-off-by: Philippe Schenker <[e-mail]>
Acked-by: Marcel Ziswiler <[e-mail]>
Reviewed-by: Oleksandr Suvorov <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

arch/arm/boot/dts/imx6ull-colibri-eval-v3.dtsi

···
 		stdout-path = "serial0:115200n8";
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_snvs_gpiokeys>;
+
+		power {
+			label = "Wake-Up";
+			gpios = <&gpio5 1 GPIO_ACTIVE_HIGH>;
+			linux,code = <KEY_WAKEUP>;
+			debounce-interval = <10>;
+			wakeup-source;
+		};
+	};
+
 	/* fixed crystal dedicated to mcp2515 */
 	clk16m: clk16m {
 		compatible = "fixed-clock";