Remove AOSP su
Add a static libf2fs_sparseblock for minvold
Fix build for static lib and executable

This seems to have been missed in aad1acc

Change-Id: I9973743dbd91dbf29691118a577f2588da8ec403
Yet another MMC discard pain in the ass

 * Secure discard on this device is painfully slow. Use regular
   discard until the issue is sorted out.

Change-Id: Ib8ccb12829385aa267253f772e243bef8850f455