iam-instance-profile modue: Expose IAM role id

[psibi]

Please also note that these are not hard requirements, but merely serve to define what maintainers are looking for in PR's. Including these will more likely lead to your PR being reviewed and accepted.

• [x] Update the changelog
• [x] Make sure that modules and files are documented. This can be done inside the module and files.
• [ ] Make sure that new modules directories contain a basic README.md file.
• [ ] Make sure that the module is added to tests/main.tf
• [x] Make sure that the linting passes on CI.
• [ ] Make sure that there is an up to date example for your code:
  • For new modules this would entail example code for how to use the module or some explanation in the module readme.
  • For new examples please provide a README explaining how to run the example. It's also ideal to provide a basic makefile to use the example as well.
• [ ] Make sure that there is a manual CI trigger that can test the deployment.

[mcgirr]

@ketzacoatl I'm going to update the merge conflicts on this MR but I'd like to fast track getting this merged. I have a WIP change for the single-node-asg module that uses the iam-instance-profile module and I need the changes that this MR makes there.

Edit: Actually I just need iam_role_arn and that's already available. I'll still take a look at the merge conflict with CHANGELOG.md