dt-bindings: arm: hisilicon,cpuctrl: Merge "hisilicon,hix5hd2-clock" into parent binding

The "hisilicon,hix5hd2-clock" is simple enough to just add it into its
parent node binding, "hisilicon,cpuctrl".

This fixes a warning that "hisilicon,hix5hd2-clock" is missing a schema.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230707210700.869060-1-robh@kernel.org


Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>