leds: rgb: leds-qcom-lpg: Add support for high resolution PWM

Certain PMICs like PMK8550 have a high resolution PWM module which can
support from 8-bit to 15-bit PWM. Add support for it.

Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230407223849.17623-3-quic_amelende@quicinc.com