license for setup_sdcard.sh

Hi Robert,

The Linaro project has a script that started as your setup_sdcard.sh called linaro_media_create. As part of our release process we need to have licenses for our files and since our script is based on yours, your choice of license affects what choices we have. So long story short, your file has no license included so care to add one or just tell us what the license is so we can give our script a compatible if not identical one?

Thanks John