hns3 udma: support of DCA

driver inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I85R2F


CVE: NA

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This patch support DCA mode. DCA(dynamic context attach)
is a feature that can reduce memory usage. Each TP must
have a sending queue to store wqe. In sparse I/O scenarios,
maintaining send queue for each TP is a waste of memory.
DCA provides a way to dynamically expand or shrink the
sending queue. DCA may cause a performance loss.

Signed-off-by: Weibo Zhao <zhaoweibo3@huawei.com>