panfrost: cmdstream rework
This is an attempt at cleaning up the HW descriptor emission logic in order to
1/ get a cleaner/more comprehensive code base 2/ avoid state leaks between draw/launch_grid calls
Next on the list is working a some kind of HW desc caching for all !job descriptors that can be re-used between draws (I have something working for shader_meta descs that I'll post once this series is merged).
Edited by Boris Brezillon