Merge branches 'per-cpu-thread-hotplug-v3-fixed', 'task-placement-v1', 'cpu-hotplug-get_online_cpus-v1', 'arm-asymmetric-support-v3-v3.6-rc1' and 'config-fragments' into big-LITTLE-MP-v7

Updates:
- Based on v3.6-rc3
- per-task-load-average-v3
- applied ARM-Add-HMP-scheduling-support-for-ARM-architecture to
  task-placement-v1 branch
- applied Tixy's patch from fast-slow-cpu-dt-v1 to task-placement-v1 as they are
  somewhat related only.

Commands used for merge:
$ gco -b big-LITTLE-MP-v7 v3.6-rc3
$ git merge per-cpu-thread-hotplug-v3-fixed per-task-load-average-v3
task-placement-v1 cpu-hotplug-get_online_cpus-v1
arm-asymmetric-support-v3-v3.6-rc1 config-fragments