net: hns3: refine function hclge_cfg_mac_speed_dup_hw()

mainline inclusion
from mainline-master
commit e46da6a3
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4M1HB
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e46da6a3d4d3



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To reuse the code of converting speed of driver to speed of firmware in
function hclge_cfg_mac_speed_dup_hw(), encapsulate them into a new
function hclge_convert_to_fw_speed().

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>