ascend/svm: Support pinned memory size greater than 2GB

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4DZ7Q


CVE: NA

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If the memory size of a single pin operation exceeds 2GB,
the memory size required for storing pages exceeds 4MB.
In this case, the allocation using kcalloc fails.

Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>