soc: hisilicon: kunpeng_hccs: Add used HCCS types sysfs

Kunpeng_hccs driver supports multiple HCCS types used on one platform at
the same time. In this case, to find which HCCS types are used on the
platform the user needs to scan the type attribute of all ports, which is
unfriendly to the user. In addition, the aggregated information is also
useful for global control like the low power feature.
So add the sysfs to show all HCCS types used on the platform.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>