ARM: Kirkwood: Convert NSA310 to use gpio-poweroff driver

Remove the C code and add a Device Tree node for gpio-poweroff.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/arch/arm/boot/dts/kirkwood-nsa310.dts b/arch/arm/boot/dts/kirkwood-nsa310.dts
index 2dc1d09..85cce36 100644
--- a/arch/arm/boot/dts/kirkwood-nsa310.dts
+++ b/arch/arm/boot/dts/kirkwood-nsa310.dts
@@ -142,6 +142,11 @@
 		};
 	};
 
+	gpio_poweroff {
+		compatible = "gpio-poweroff";
+		gpios = <&gpio1 16 0>;
+	};
+
 	regulators {
 		compatible = "simple-bus";
 		#address-cells = <1>;