arm64: zynqmp: Use keycode from input/input.h

Instead of hardcoding numbers.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/dts/zynqmp-zcu102-revA.dts b/arch/arm/dts/zynqmp-zcu102-revA.dts
index efa94a1..c04e37d 100644
--- a/arch/arm/dts/zynqmp-zcu102-revA.dts
+++ b/arch/arm/dts/zynqmp-zcu102-revA.dts
@@ -11,6 +11,7 @@
 
 #include "zynqmp.dtsi"
 #include "zynqmp-clk-ccf.dtsi"
+#include <dt-bindings/input/input.h>
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/pinctrl/pinctrl-zynqmp.h>
 #include <dt-bindings/phy/phy.h>
@@ -51,7 +52,7 @@
 		sw19 {
 			label = "sw19";
 			gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
-			linux,code = <108>; /* down */
+			linux,code = <KEY_DOWN>;
 			gpio-key,wakeup;
 			autorepeat;
 		};