Small changes to onshore hawcstab2 files

[jennirinker]

Purpose

I had some small differences in the HAWCStab2 files for the onshore turbine (e.g., generator efficiency) so I fixed them. There is also a new .opt file for the Onshore turinie.

Type of change

What types of change is it?

• [ x] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (non-backwards-compatible fix or feature)
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes, no API changes)
• [ ] Documentation update
• [ ] Maintenance update
• [ ] Other (please describe)

Testing

None relevant.

Checklist

Put an x in the boxes that apply.

• [ ] I have run existing tests which pass locally with my changes
• [ ] I have added new tests or examples that prove my fix is effective or that my feature works
• [ ] I have added necessary documentation

[jennirinker]

@ptrbortolotti @gbarter Sorry for this, it's some small changes so I wasn't sure if it should be on master or develop. If it looks ok to merge, please do so when you're comfortable.

[gbarter]

There are some other pending updates in develop, so let's put in there and do a bigger PR into master.