hns3 udma: mmap doorbell address to uar page

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


CVE: NA

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This patch mmap doorbell address of hardware to
uar page. Doorbell address is in bar23 area.

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