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

Changes in this version:
- Update to 15.11 release of LSK 3.18. This adds backports of PCIe
  and OPPv2.

Issues when running Android on Juno r2:
- Android will always use the Sky2 PCIe ethernet hardware, even if
  it has no network cable and the other network hardware does have a
  connection. This is because PCIe ethernet is getting named 'eth0' by
  kernel and Android always uses that.
- On reboot we get a 'synchronous external abort' in sky2_get_stats
  (part of the driver for the PCIe ethernet). This doesn't prevent
  reboot occurring and the error also occurs on vanilla Linux 4.4-r3
  (with graphics drivers added).