The next code optimization :)

+ PM / hibernate: Avoid overflow in hibernate_preallocate_memory().
ported from
(https://github.com/jrior001/Torched_kernel/commit/7094547c201149598a2bd90ef7f04d477dffae1b)
+ lib/int_sqrt.c: optimize square root algorithm. ported from
(https://github.com/flar2/ElementalX-m7-5.0/commit/c5cd477d931d2fa7a9c9a4aa97759c3a959ba954)
+ simple GPU governor. ported from
(https://github.com/flar2/ElementalX-m7-5.0/commit/d68c8f26c776530e3003cde160f8587916adcd65)
+ fs/dyn_sync_cntrl: dynamic sync control. ported from
(https://github.com/motley-git/kernel-Nexus4/commit/d08744e537517585fb82b12c53912f74d445a4fb)