arm64: dts: freescale: imx8dxl: fix sc_pwrkey's property name linux,keycode

linux,keycode should be "linux,keycodes" according binding-doc
Documentation/devicetree/bindings/input/fsl,scu-key.yaml

Fixes: f537ee7f ("arm64: dts: freescale: add i.MX8DXL SoC support")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8dxl.dtsi

@@ -164,7 +164,7 @@ rtc: rtc {
 
 		sc_pwrkey: keys {
 			compatible = "fsl,imx8qxp-sc-key", "fsl,imx-sc-key";
-			linux,keycode = <KEY_POWER>;
+			linux,keycodes = <KEY_POWER>;
 			wakeup-source;
 		};