libavb: Move all A/B functionality into separate libavb_ab/ directory. am: baf59e232e am: 5e299321db
am: ac33257261

Change-Id: I0ee3a21d37d7394c8a58df535b34e49ee3723f6e
tree: 7af1fad67264fdc4b6c210cd027b31c64c9ec569
  1. boot_control/
  2. libavb/
  3. libavb_ab/
  4. test/
  5. Android.mk
  6. avbtool
  7. LICENSE
  8. README