UNIC: PF supports MAC loopback

driver inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I850RQ


CVE: NA

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Loopback can be used to test the connectivity of the
system hardware.

This patch supports loopback by using standard tools with
packets sent in UB packet format.

Signed-off-by: Haibin Lu <luhaibin10@hisilicon.com>
Signed-off-by: Junxin Chen <chenjunxin1@huawei.com>