etmem: enable etmem configurations

euleros inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8T1MB?from=project-issue


CVE: NA

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This patch enables CONFIG_ETMEM, CONFIG_ETMEM_SCAN,
CONFIG_ETMEM_SWAP for etmem.

Signed-off-by: Yuchen Tang <tangyuchen5@huawei.com>