dhugetlb: only support 1G/2M hugepage and ARM64_4K_PAGES

hulk inclusion
category: feature
bugzilla: 46904, https://gitee.com/openeuler/kernel/issues/I6BDME


CVE: NA

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For now, we only support 1G and 2M hugepage on arm64 with 4K pages.
So restrict the config depends on ARM64_4K_PAGES and only setting hpool
for 1G and 2M hugepage.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>