nvc0: implement compute support for nvc0

V2:
- Add Christoph Bumiller as an author of nvc0_compute
- fix/improve/extend compute support. Patch by Christoph Bumiller
- Fix global memory setup
- Fix a graphical issue by rebinding all the 3D constant buffers
- Add experimental support for nvc8/d7/d9

Tested on nvc0, nvc1, nvcf and nvd9.
nvc0: implement MP performance counters for nvc0:nvd9

V2:

- s/c1/c0/ and s/C1/C0

V3:

- rename COUNT_GRED to GRED_COUNT and COUNT_ATOM to ATOM_COUNT
nvc0: screen->base.class_3d >= NVC0_3D_CLASS is always true on nvc0
nvc0: Correctly sort names of MP counters for nve4