ARM: dts: imx28-duckbill-2-enocean: Remove unnecessary #address/#size-cells

Remove unnecessary #address-cells/#size-cells to fix the following
DTC warnings:

arch/arm/boot/dts/imx28-duckbill-2-enocean.dtb: Warning (avoid_unnecessary_addr_size): /gpio-keys: unnecessary #address-cells/#size-cells without "ranges" or child "reg" propert
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx28-duckbill-2-enocean.dts

@@ -206,8 +206,6 @@
 
 	gpio-keys {
 		compatible = "gpio-keys";
-		#address-cells = <1>;
-		#size-cells = <0>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&enocean_button>;