Merge tag 'big-LITTLE-MP-13.08' into for-lsk

This merge is intended to tidyup the history of the big.LITTLE MP
patchset to enable ongoing maintenance of a standalone MP branch.

The only code change introduce by this merge is to add commit
0d5ddd14 (HMP: select 'best' task for migration rather than 'current')
This change is already in the Linaro Stable Kernel as commit
c5021c1eb9c73f38209180c65bd074ac70c97587