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>