net: hns3: add tx push support in hns3 ring param process

This patch adds tx push param to hns3 ring param and adapts the set and get
API of ring params. So users can set it by cmd ethtool -G and get it by cmd
ethtool -g.

Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>