I faced the same problem on Gentoo system. My solution was to downgrade kernel to 4.11.12. But I think any 4.11 should work
Unfortunately, I could not get this to work. Similar problem. X230 with two monitors connected to a docking station. I can get the xorg.conf (no modelines, thank goodness) to cause a black screen when I switch to a tty, but that's it. Tried some tweaks, but those only caused the graphical system not to work at all after boot. And even then, no ttys. Oh well. Frustrating.