net: hns3: support arp proxy

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8GQDK


CVE: NA

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In RoH mode, the IP and MAC of network devices have a special mapping
relationship. The mapping is show as followed:
IP: a.b.c.d    <------>    MAC: 0.0.0.b.c.d
Thus, the arp request for find the mac of a ip is not necessary to send
to network. The driver can generate a response arp to the protocol stack
based on above mapping relationship.

Arp proxy is designed to acheive the above function. The scope of ARP
proxy include all ARP request message including vlan, except free ARP
request and tunnel message.

Signed-off-by: Peiyang Wang <wangpeiyang1@huawei.com>