Yo paul,
While the code is compilable there is a problem with the display not working on the htc vive, though it works for the oculus. I'm having a little trouble atm with my hardware sporadically detecting the vive so I have not yet been able to resolve the issue.
To compile there are some cmake build options, or alternatively you can just include the platform/input/openvr files and manually add in the openvr sdk from
https://github.com/ValveSoftware/openvr
Note that openvr only works with d3d11, it will not work with d3d9. So you need the d3d11 engine code and the relevant files for the game folder in order to be able to use it.