Move add_route_obs before global routing
Move add_route_obs before global routing

On a design with many large macros, FastRoute is placing guides right
through the middle of those macros. TritonRoute never manages to recover
from this and I end up with over a thousand DRC issues due to these tracks.

In order to stop this I added an GLB_RT_OBS line covering all the macros,
but that didn't help FastRoute because the obstructions get added after global
routing. Moving add_route_obs earlier fixes this.

efabless/openlane,efabless/openlane,efabless/openlane,efabless/openlane