net: hns3: add priv flags support to switch limit promisc mode

mainline inclusion
from mainline-v5.11-rc1
commit 5e7414cd
category: feature
bugzilla: 173966
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5e7414cdf1abea7e2fc19a3190aa7b0d0b1e629d



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Currently, the tx unicast promisc is always enabled when promisc
mode on. If tx unicast promisc on, a function will receive all
unicast packet from other functions belong to the same port.
Add a ethtool private flag to control whether enable tx
unicast promisc. Then the function is able to filter the
unknown unicast packets from other function.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Yongxin Li <liyongxin1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>