RDMA/hns: Load the RoCE dirver automatically

To enable the linux-kernel system to load the hns-roce-hw-v2 driver
automatically when hns-roce-hw-v2 is plugged in pci bus, it need to
create a MODULE_DEVICE_TABLE for expose the pci_table of
hns-roce-hw-v2 to user.

Signed-off-by: Lijun Ou <oulijun@huawei.com>
Reported-by: Zhou Wang <wangzhou1@hisilicon.com>
Tested-by: Xiaojun Tan <tanxiaojun@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>