net: hns3: add support for page_pool_get_stats

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8GK5Q


CVE: NA

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Add support for page_pool_get_stats, then the hns3 driver
can get page pool statistics by ethtool.

Signed-off-by: Jian Shen <shenjian15@huawei.com>