Configure TARGET_INCREMENTAL_OTA_VERBATIM_FILES.

The latest changes in android_build (in either xdarklight's or Quarx2k's
forks) make it possible to configure it on a per-device level.
Merge pull request #32 from xdarklight/cm11.0-2.6.32

Configure TARGET_INCREMENTAL_OTA_VERBATIM_FILES.