!1083 LoongArch: fix system hang caused by 2k500 bmc driver

Merge Pull Request from: @Hongchen_Zhang 
 
when we test the 2k500 bmc,the system hang when send the following command:
[loongson@localhost ~]# ipmi mc reset cold

After apply this PR,the problem disappeared. 
 
Link:https://gitee.com/openeuler/kernel/pulls/1083

 

Reviewed-by: Guo Dongtai <guodongtai@kylinos.cn>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>