boards: custom_plank: instantiate blink-gpio-led

Define an instance of a blink-gpio-led. Since custom_plank is in reality
a nRF52840DK, this uses LED0 as the blink-gpio-led.

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>

Author: gmarull

boards/vendor/custom_plank/custom_plank.dts

@@ -21,6 +21,12 @@
 		compatible = "zephyr,example-sensor";
 		input-gpios = <&gpio0 11 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
 	};
+
+	blink_led: blink-led {
+		compatible = "blink-gpio-led";
+		led-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+		blink-period-ms = <1000>;
+	};
 };
 
 &uicr {