- EC Lib

This wraps Blizzard driverlib and implements the EC chip interface defined
by Google. See below diagram for architecture.


  +--------------------+
  |   Host BIOS/OS     |
  +--------------------+

 ---- host interface ----

  +--------------------+
  | Google EC features |
  +--------------------+

 ---- chip interface ----  The interface is defined in
                           src/platform/ec/chip_interface/*.
  +--------------------+   But the real implementation is in EC Lib.
  |       EC Lib       |
  +--------------------+
  | Blizzard low level |
  |   driver, the      |
  |   driverlib.       |
  +--------------------+