The HLCDC IP available on some Atmel SoCs (i.e. at91sam9n12, at91sam9x5
family or sama5d3 family) exposes 2 subdevices:
- a display controller (controlled by a DRM driver)
- a PWM chip

This patch adds documentation for atmel-hlcdc DT bindings.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NAnthony Harivel <anthony.harivel@emtrion.de>
Tested-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>