workqueue: implement NUMA affinity for single thread workqueue

euleros inclusion
category: feature
feature: Implement NUMA affinity for order workqueue

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Currently, single thread workqueue only have single pwq, all of
works are queued the same workerpool. This is not optimal on
NUMA machines, will cause workers jump around across node.

This patch add a new wq flags __WQ_DYNAMIC,  this new kind of
single thread workqueue creates a separate pwq covering the
intersecting CPUS for each NUMA node which has online CPUS
in @attrs->cpumask instead of mapping all entries of numa_pwq_tbl[]
to the same pwq. After this, we can specify the @cpu of
queue_work_on, so the work can be executed on the same NUMA
node of the specified @cpu.
This kind of wq only support single work, multi works can't guarantee
the work's order.

Signed-off-by: Biaoxiang Ye <yebiaoxiang@huawei.com>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>