CameraWrapper: rework defines

* Set the various needed flags in device trees rather than checking
  device variant in the camera wrapper's makefile.
* Move checks after CLEAR_VARS. You know, so they actually work.
  As it urns out, you can't clear variables after setting them and
  expect them to work.
* Enable some magic for newer Samsungs. Need to send a magic command
  (1508) to the camera. Nobody knows what this number actually stands
  for. Well...maybe nishu does...

Change-Id: I90a83658e3e3178c4dc92aba885d2b991f7b3811