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

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>