This patch introduces a new C state which allows MPU to go to WFI but keeps
the core domain active. This offers a much better wakeup latency (3us vs
10s of us for the current C1) at the cost of a higher power consumption.

Signed-off-by: Peter 'p2' De Schrijver <peter.de-schrijver@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>