dt-bindings: arm: hisilicon: convert Hi6220 domain controller bindings to json-schema

Convert the Hisilicon Hi6220 domain controllers binding to DT schema
format using json-schema. All of them are grouped into one yaml file, to
help users understand differences and avoid repeated descriptions.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20200930031712.2365-16-thunder.leizhen@huawei.com
Signed-off-by: Rob Herring <robh@kernel.org>