!479 LoongArch: update network related default config

Merge Pull Request from: @Hongchen_Zhang 
 
keep the network related default configurations same with other architectures,
so network related tools (bridge,tc,...) can work normally on LoongArch.
After apply this PR,the following test passed:
1. git clone git@gitee.com:src-openeuler/iproute.git
2. cd iproute
3. rpmbuild -ba iproute.spec 
 
Link:https://gitee.com/openeuler/kernel/pulls/479

 

Reviewed-by: Guo Dongtai <guodongtai@kylinos.cn>
Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>