asahi,agx: make api manage queue creation

The internal queue on agx_device is unused by agxv (as agxv creates it's own queue). Let's make gallium create it's own queue so that agxv and the gallium driver are consistent here. Some of the stuff related to submission on agx_device is also unused by both drivers, so toss that as well.

Seemed to run fine with glxgears and weston-simple-egl, so I'll assume it's working.