ARM: dts: samsung: exynos5420-peach: Enable cros-ec-spi as wake source

The cros_ec driver currently assumes that cros-ec-spi compatible device
nodes are a wakeup-source even though the wakeup-source property is not
defined.

Add the wakeup-source property to all cros-ec-spi compatible device
nodes to match expected behavior.
Signed-off-by: Mark Hasemeyer <markhas@chromium.org>
Link: https://lore.kernel.org/r/20231220165423.v2.6.I06b059021de1bf6103e60a73211f078f2af75d17@changeidSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

arch/arm/boot/dts/samsung/exynos5420-peach-pit.dts

@@ -967,6 +967,7 @@ cros_ec: cros-ec@0 {
 		reg = <0>;
 		spi-max-frequency = <3125000>;
 		google,has-vbc-nvram;
+		wakeup-source;
 
 		controller-data {
 			samsung,spi-feedback-delay = <1>;