ARM: dts: samsung: exynos4412-midas: use Linux event codes for input keys

Use event codes with linux-event-codes.h included for input keys on
midas.

Signed-off-by: Raymond Hackley <raymondhackley@protonmail.com>
Link: https://lore.kernel.org/r/20231017101647.62770-1-raymondhackley@protonmail.com
[krzysztof: drop header include, because it is already provided by
 dt-bindings/input/input.h]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Author: wonderfulShrineMaidenOfParadise

arch/arm/boot/dts/samsung/exynos4412-midas.dtsi

@@ -137,21 +137,21 @@
 
 		key-down {
 			gpios = <&gpx3 3 GPIO_ACTIVE_LOW>;
-			linux,code = <114>;
+			linux,code = <KEY_VOLUMEDOWN>;
 			label = "volume down";
 			debounce-interval = <10>;
 		};
 
 		key-up {
 			gpios = <&gpx2 2 GPIO_ACTIVE_LOW>;
-			linux,code = <115>;
+			linux,code = <KEY_VOLUMEUP>;
 			label = "volume up";
 			debounce-interval = <10>;
 		};
 
 		key-power {
 			gpios = <&gpx2 7 GPIO_ACTIVE_LOW>;
-			linux,code = <116>;
+			linux,code = <KEY_POWER>;
 			label = "power";
 			debounce-interval = <10>;
 			wakeup-source;