The dri options are optional. When the dri options are not provided
the WSI will not  use adaptive sync.

FWIW I think for xf86-video-amdgpu this still requires an X11 config
option, so only people who opt in can get possible regressions from this.

So then the remaining question is: why do this in the WSI?

It has been suggested in another MR that the application sets this.
However, I disagree with that as I don't think we'll ever get a
reasonable set of applications setting it.

The next questions is whether this can be a layer. It definitely
can be as implemented now. However, I think this generally fits
well with the function of the WSI. Furthemore, for e.g. the DISPLAY
WSI this is much harder to do in a layer.

Of course, most of the WSI could almost be a layer, but I think
this still fits best in the WSI.

Acked-by: Jason Ekstrand <jason@jlekstrand.net>