Juno/vexpress Android kernel based on 3.18 version of Linaro Stable Kernel (LSK)

Changes in this version:
- Upgrade Mali drivers to r8p0.
- Add devicetree for Juno r2.
- Add CONFIG_DEVMEM to enable juno_energy instrument.
- Make SCPI driver timeout messages after 10 seconds and BUG if that
  happens. Because driver and mailbox framework don't support
  cancelling requests so any timeouts will lead to data structure
  corruption and unpleasant bugs. I.e. the crashes reported in
  https://bugs.linaro.org/show_bug.cgi?id=1841