rfc/wip ttm get rid of binding branch

[Dave Airlie]

Spent today trying to straighten out some of the ideas I had for
dropping bind/unbind paths into drivers.

https://github.com/airlied/linux/commits/ttm-no-more-bind

I think it mostly trends to the right place, the bind/unbind paths all
end up in drivers, you get a move/invalidate_notify or move_notify in
drivers (only drm_gem_vram, still uses move_notify).

I've only booted nouveau with this so far, just looking to see if it's
a good idea or maybe I've gone too far :-P

Dave.