dt-bindings: arm: hisilicon: convert hisilicon,cpuctrl bindings to json-schema

Convert the Hisilicon CPU controller binding to DT schema format using
json-schema.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20200929141454.2312-12-thunder.leizhen@huawei.com


Signed-off-by: Rob Herring <robh@kernel.org>