config: enable set the max iova mag size to 128

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7ASVH


CVE: NA

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iova mag size will be iova_rcache size to 128, to support more
concurrency in iova allocation, and can fix the problem dixcribe
in bugzilla.

Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>