sched/core: Disable CONFIG_SCHED_CORE by default

mainline inclusion
from mainline-v5.14-rc1
commit d2343cb8
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5OOWG
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d2343cb8d154fe20c4499711bb3a9af2095b2b4b



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This option at minimum adds extra code to the scheduler - even if
it's default unused - and most users wouldn't want it.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Lin Shengwang <linshengwang1@huawei.com>
Reviewed-by: lihua <hucool.lihua@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>