hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I737X1

-------------------------------

Expand qos_level from {-1,0} to [-2, 2], to distinguish the tasks expected
to be with extremely high or low priority level. Using qos_level_weight
to reweight the shares when calculating group's weight. Meanwhile,
set offline task's schedule policy to SCHED_IDLE so that it can be
preempted at check_preempt_wakeup.
Signed-off-by: NZhao Wenhui <zhaowenhui8@huawei.com>