Juno/vexpress/FVP kernel based on latest version of Linux (v4.9-rc2)

Changes in this version:
- Update to latest version of Linux. This includes new TDA998x audio
  support and PL330 DMA fixes which mean we can now support audio on
  Juno with just device-tree changes rather than needing out-of-tree
  code.
- Add cpu idle to Foundation model device-tree.
- Remove shutdown and reboot mcc nodes from FVP device-trees. This
  means these functions will now be performed via PSCI.

Issues:
- Mali driver omitted because it doesn't compile with latest Android
  sync APIs