!3005 [sync] PR-1617: LoonArch: KVM: fix vcpu timer

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/1617 
 
Fix vcpu timer initialize, saved, restore and triggered functions.
As the previous code does not init vcpu timer, and the timer value
should add time value instead of ticks value to calculate the expire 
time when vcpu timer triggered.
 
 
Link:https://gitee.com/openeuler/kernel/pulls/3005

 

Reviewed-by: Kevin Zhu <zhukeqian1@huawei.com>
Reviewed-by: Mao Bibo <maobibo@loongson.cn>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>