Add Debian ppc64 templates
Created by: doublej472
This is a preliminary PR, this only makes sense to view changes relative to doublej472/fix-ubuntu, not master. As soon as that PR is merged this will be ready to be merged. In the mean time, this has been created so that it can be reviewed by people who are interested.
This should be good to review on it's own now
This PR adds support for Debian 8 on ppc64 and ppc64le, and Debian 9 for ppc64le. The scripts are heavily based off of the Ubuntu 16.04 PR, with some Debian specific changes.
A major change that needed to be made is that Debian 8 (BE & LE) does not include ppc64-diag
in the package repos. This means that we have to build them separately and add them to our own apt repository. Doing so requires that we add our GPG key and repository information to the apt sources before we can install our packages. Debian 9 packages this, so we don't have to do the same thing there.