dt-bindings: leds: Replace moonlight with indicator in mt6360 example

Replace moonlight with indicator in mt6360 example to prevent the below
build error:

Error: Documentation/devicetree/bindings/leds/leds-mt6360.example.dts:114.24-25
syntax error
FATAL ERROR: Unable to parse input tree
make[1]: *** [scripts/Makefile.lib:385:
Documentation/devicetree/bindings/leds/leds-mt6360.example.dt.yaml]
Error 1

Link: https://lore.kernel.org/lkml/CAL_JsqJRMVE163LaHTbtFARc4f_qg33bfQx+sD3ukce_xQF+gA@mail.gmail.com/Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Reviewed-by: Gene Chen <gene_chen@richtek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

Documentation/devicetree/bindings/leds/leds-mt6360.yaml

@@ -133,7 +133,7 @@ examples:
      };
      led@3 {
        reg = <3>;
-       function = LED_FUNCTION_MOONLIGHT;
+       function = LED_FUNCTION_INDICATOR;
        color = <LED_COLOR_ID_WHITE>;
        led-max-microamp = <150000>;
      };