ARM: mvebu: Add DT entry for ReadyNAS 102 to use gpio-poweroff driver

Without that fix, at the end of the shutdown process, the board is
still powered (led glowing, fan running, ...).
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/armada-370-netgear-rn102.dts

@@ -57,6 +57,11 @@ backup_led_pin: backup-led-pin {
 					marvell,pins = "mpp56";
 					marvell,function = "gpio";
 				};
+
+				poweroff: poweroff {
+					marvell,pins = "mpp8";
+					marvell,function = "gpio";
+				};
 			};
 
 			mdio {
@@ -176,4 +181,11 @@ button@3 {
 		};
 	};
 
+	gpio_poweroff {
+		compatible = "gpio-poweroff";
+		pinctrl-0 = <&poweroff>;
+		pinctrl-names = "default";
+		gpios = <&gpio0 8 1>;
+	};
+
 };