LU-13258 libcfs: make apply_workqueue_attrs() available for Lustre

LU-13258 libcfs: make apply_workqueue_attrs() available for Lustre

Currently Lustre work queues can run on any core which introduces
noise on the system. The linux kernel has a function called
apply_workqueue_attrs() which allows you to control which cores
a work queue will execute on. Manually export this function so
Lustre can use it.

Test-Parameters: trivial

Change-Id: I467539cb8def7029fa9dfff2386234de5e0fe133
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/37613
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>