net: hns3: add function type check for debugfs help information

PF supports all debugfs command, but VF only supports part of
debugfs command. So VF should not show unsupported help information.

This patch adds a check for PF and PF to show the supportable help
information.

Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>