Use offmode charging blobs from m7

* Use offmode charging blobs from m7 (m7wlv OTA 5.28.605.2) to enable
  charging images support
* Shrink charging images from m7 (1080px width) proportionally for
  fireball (540px width).
* Take this opportunity to do a little directory cleanup, too.

Change-Id: I24d321ab75af3207d9946a6592888c8dc5bcc4fe