Merge branches 'per-cpu-thread-hotplug-v3-fixed', 'fast-slow-cpu-dt-v1', 'cpu-hotplug-get_online_cpus-v1' and 'config-fragments' into big-LITTLE-MP-v6

Rebased over: v3.6-rc2

- Removed - arm-asymmetric-support-v3-v3.6-rc1
- Included - cpu-hotplug-get_online_cpus-v1

$ gco -b big-LITTLE-MP-v6 v3.6-rc2
$ git merge per-cpu-thread-hotplug-v3-fixed per-task-load-average-v2 task-placement-v1 fast-slow-cpu-dt-v1 cpu-hotplug-get_online_cpus-v1 config-fragments