sched/fair: Add snapshot of load-balancing changes

This snapshot is taken from msm-4.14 as of commit 871eac76e6be567
(Merge "msm: pcie: provide option to override maximum GEN speed").

Change-Id: I75555a04020478e8d589b6a0fba209501c360dad
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>