mm/dynamic_pool: disable THP for task attached with dpool

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8S9BY


CVE: NA

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There is no way to alloc THP pages from dpool for now, so must disable THP
for task attached with dpool, oterwise it may prefer to alloc THP pages
from buddy system which is not desired.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>