net: hns3: device specifications add number of mac statistics

mainline inclusion
from mainline-master
commit 4e4c03f6
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4I7P7
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4e4c03f6ab63



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Currently, driver queries number of mac statistics before querying mac
statistics. As the number of mac statistics is a fixed value in firmware,
it is redundant to query this number everytime before querying mac
statistics, it can just be queried once in initialization process and
saved in device specifications.

Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Yongxin Li <liyongxin1@huawei.com>
Signed-off-by: Junxin Chen <chenjunxin1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>