[Intel-gfx] please revert 593d7c3ce43229a662642245f2fa4d84583b1ca1 ASAP

[Dave Airlie]

This commit breaks the eDP panel on the my HP Elitebook 2540p,
reverting it brings the panel back to life.

I'm happy to debug this later, but at this point in the release for
2.6.37 we should just revert this.

It looks like it tries to lock the panel to a 16200 clock @ 2 lanes
when it really wants a 27000 clock at one lane.

Dave.