dt-bindings: clk: sunxi-ng: document two Allwinner A523 CCUs

The Allwinner A523/T527 SoCs have four CCUs, this adds the binding for
the main and the PRCM R-CCU.

The source clock list differs in some annoying details, and folding this
into the existing Allwinner CCU clock binding document gets quite
unwieldy, so create a new document for these CCUs.
Add the new compatible string, along with the required input clock
lists. This conditionally describes the input clock lists, to make
adding support for the other two CCUs easier.

Also add the DT binding headers, listing all the clocks with their ID
numbers.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250307002628.10684-5-andre.przywara@arm.com


Signed-off-by: Chen-Yu Tsai <wens@csie.org>