dt-bindings: clock: sun8i-de2: Add H6 DE3 clock description

This commit adds necessary description and dt includes for H6 DE3 clock.
It is very similar to others, but memory region has some additional
registers not found in DE2.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

dt-bindings: add binding for the Allwinner DE2 CCU

Allwinner "Display Engine 2.0" contains some clock controls in it.

In order to add them as clock drivers, we need a device tree binding.
Add the binding here.

Also add the device tree binding headers.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>