ascend inclusion
category: feature
bugzilla: NA
CVE: NA

-------------------------------------------------

Add a flag VM_SHAREPOOL to avoid vfree() a shared kva.
Reviewed-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>