dt-bindings: leds: leds-qcom-lpg: Add support for LPG PPG

Update leds-qcom-lpg binding to support LPG PPG.

Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231221185838.28440-3-quic_amelende@quicinc.com


Signed-off-by: Lee Jones <lee@kernel.org>