config: enable CONFIG_SCHED_STEAL by default

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8PIYZ


CVE: NA

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Enable steal tasks by default to improve CPU utilization

Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Cheng Yu <serein.chengyu@huawei.com>