Allwinner A10 is now driven by sunxi-ng CCU driver.

Add devicetree binding for it.
Acked-by: NRob Herring <robh@kernel.org>
Reviewed-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NPriit Laes <plaes@plaes.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>