dt-bindings: pwm: amlogic: Add optional power-domains

On newer SoCs, the PWM hardware can require a power domain to operate
so add corresponding optional property.

Signed-off-by: George Stark <gnstark@salutedevices.com>
Acked-by: Conor Dooley <conor@kernel.org>
Link: https://lore.kernel.org/r/20240710234116.2370655-2-gnstark@salutedevices.com


Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>