sched: programmable: Add a tag for the task group

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8OIT1



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Add a tag for the task group, to support the tag-based
scheduling mechanism.

The tag is used to identify a special task or a type of
special tasks, there are many special tasks in the real
world, such as foreground and background tasks, online
and offline tasks, ect. so, we can identify such special
tasks, and execute specific policies.

Signed-off-by: Chen Hui <judy.chenhui@huawei.com>
Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>
Signed-off-by: Hui Tang <tanghui20@huawei.com>
Signed-off-by: Guan Jing <guanjing6@huawei.com>