dt-bindings: leds: Add missing references to common LED schema

'led' nodes should have a reference to LED common.yaml schema. Add it where
missing and drop any duplicate properties.

Acked-by: Lee Jones <lee@kernel.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221207204327.2810001-2-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>