!868 LoongArch: fix compile error caused by __ffs not defined

Merge Pull Request from: @Hongchen_Zhang 
 
after commit 0cba0556 ("cpumask: introduce for_each_cpu_or")
LoongArch code can not compile,the reason is __ffs is not found,
change the bitops.h include order to make it fine. 
 
Link:https://gitee.com/openeuler/kernel/pulls/868

 

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