!867 arm64: kdump: Avoid reserving low memory repeatedly

Merge Pull Request from: @ci-robot 
 
PR sync from:  Li Huafei <lihuafei1@huawei.com>
 https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/thread/KUHVPGLDH5VREMJJOSMW2VRWWHEG5OML/ 
 
 
Link:https://gitee.com/openeuler/kernel/pulls/867

 

Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>