Remove unneeded diy build include directory

The diy build configured files are all located by the include from the root vtkm include directory, so this include isn't needed

This merge request has been queued for testing. Test results may be viewed on:

• CDash (master)
• Buildbot (master) (only visible from inside Kitware)

Branch-at-master: 030b03e4

Do: merge

mentioned in commit e7924e76

merged