net: hns3: keep MAC pause mode when multiple TCs are enabled

mainline inclusion
from mainline-v5.11-rc1
commit d78e5b6a
category: feature
bugzilla: 173966
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d78e5b6a6764cb6e83668806b63d74566db36399



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Bellow HNAE3_DEVICE_VERSION_V3, MAC pause mode just support one
TC, when enabled multiple TCs, force enable PFC mode.

HNAE3_DEVICE_VERSION_V3 can support MAC pause mode on multiple
TCs, so when enable multiple TCs, just keep MAC pause mode,
and enable PFC mode just according to the user settings.

Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: li yongxin <liyongxin1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>