dt-bindings: arm: hisilicon: add missing properties into sysctrl.yaml

Add properties: #reset-cells, #address-cells, #size-cells and ranges. Due
to the Hisilicon system controller node may contains child nodes, change
the value of "additionalProperties" from "false" to "type: object". The
examples have also been updated.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20201012061225.1597-10-thunder.leizhen@huawei.com


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