dt-bindings: atmel,hlcdc: convert pwm bindings to json-schema

Convert device tree bindings for Atmel's HLCDC PWM controller to YAML
format.

Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240202001733.91455-3-dharma.b@microchip.com


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>