build: Add script to generate extra images

Change-Id: I53081c7a2b4f18bc8c8a27b04d311a6b078b2022
Use CM standard qcom naming

Change-Id: I360b3dcf1fe82140a7993189e881f9d77b571bef
[HAX] Allow per-target dtbTool

 * Revert this when fixed

Change-Id: I97ecb0448ae7bd5859454be290c5dde6248b2859