pushed preparation patch for KMS

[Dave Airlie]

Hi guys

I pushed a patch that prepares the driver accel code for the upcoming
KMS/DRI2 support.

This mainly sorts out the accel interfaces and tries to hide the mess
that supporting 25 different methods of
accel does.

Let me know if it breaks anything major, or if there is any insanity
you'd rather see not live much longer.

I've mainly tried to avoid having an #ifdef XF86DRM_MODE mass.

Dave.