freedreno: plug some leaks

The first patch sort of papers over what appears to be a small EGL leak with a few deqp-egl cases, which I need to have a closer look at. But I think it is otherwise a worthwhile change, we don't need the overhead/complexity of bo's holding a dev reference.

The second to last patch fixes a leak that had me puzzled for a couple days, until I realized that the vma, not the fd, was the thing that was holding drm dev struct files live until the process eventually exited.

The last patch is updates for kernel regs/packets, just hitching a ride.

(I'll spend some more time looking at the EGL leak, but the 2nd to last patch fixes an issue that is blocking several groups of android cts tests.)