locking: percpu-rwsem: export percpu_free_rwsem function

locking: percpu-rwsem: export percpu_free_rwsem function

Export for percpu_free_rwsem function for the external modules

Bug 200373122

Change-Id: Iec66aefc264e0c1050ee1b62e4d6d64e179bb298
Reviewed-on: https://git-master.nvidia.com/r/1637438
GVS: Gerrit_Virtual_Submit
Reviewed-by: Dipen Patel <dipenp@nvidia.com>
Tested-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Winnie Hsu <whsu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>