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

Changes in this version:
- Fixed some cpuidle problems by cherry-picking commit 8ec41987436d
  ("arm64: mm: ensure patched kernel text is fetched from PoU")
  Problem discovered, and fix suggested, by Leo Yan <leo.yan@linaro.org>
- Upate OP-TEE to latest 3.18 backport (v12)
- Add required CONFIG_SCHED_MC to EAS.conf. (Other Linaro configs have
  this so it was already enabled in 'normal' builds, this change just
  makes the requirement explicit).

Issues:
- Motherboard ethernet for Juno r1 and r2 are disabled in device-tree.