Properly handle boot images that use dt

Change-Id: Ia9ad042d704f717c3c56820f2bff1b44a5ac69e5
 bring back boot.img handling

Change-Id: I84050a17a216e87b9d58fd4afe32458e00a7f462
Merge pull request #2 from a2441918/kitkat

This commit partially reverts the previous commit of link below.