net: hns: use device_* APIs instead of of_* APIs

OF series functions can be used only for DT case. Use unified
device property function instead to support both DT and ACPI.

Signed-off-by: Kejian Yan <yankejian@huawei.com>
Signed-off-by: Yisen Zhuang <Yisen.Zhuang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>