PM / devfreq: add locking documentation for recommended_opp

OPP pointers are protected by RCU locks, the pointer validity is
permissible only under the section of rcu_read_lock to rcu_read_unlock

Add documentation to the effect.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: bcb27549f4185ca7d0168e201931613706ef2b83
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I2c0336d9941f2e1ddb42d97342c95cd61c96af44
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
1 file changed