hikey: Add factory-image generation scripts

Initial pass to add scripts to generate the hikey
factory images.

Also includes a README to explain how to use the
scripts to properly generate the files.

Change-Id: Iba66baa6b58b6565a3a64f1dad9577f51f848abc
Signed-off-by: John Stultz <john.stultz@linaro.org>
3 files changed