ANDROID: export cpuset_cpus_allowed()for GKI purpose.

Exporting the symbol cpuset_cpus_allowed() so that we can adjust a
certain type of application's CPU affinity in vendor hooks according
to our tuning policy.
Related commit: aosp/2565450

Bug: 189725786
Bug: 283222331

Signed-off-by: lijianzhong <lijianzhong@xiaomi.com>
Change-Id: I7919a893ab64bb441ab43cbb0b16825ed76d802d
(cherry picked from commit 5a7d01ed)