nvc0/pgraph: add some MP regs
nvc0/pgraph: add some MP regs

Extracted from mwk's single stepping doc.

pierremoreau/envytools,karolherbst/envytools,envytools/envytools,kfractal/envytools,MoochMcGee/envytools,pierremoreau/envytools,MoochMcGee/envytools,pierremoreau/envytools,grate-driver/envytools,MoochMcGee/envytools,envytools/envytools,grate-driver/envytools,hakzsam/envytools,pierremoreau/envytools,karolherbst/envytools,kfractal/envytools,hakzsam/envytools,karolherbst/envytools,grate-driver/envytools,MoochMcGee/envytools,karolherbst/envytools,kfractal/envytools,grate-driver/envytools,envytools/envytools,karolherbst/envytools,hakzsam/envytools,MoochMcGee/envytools,pierremoreau/envytools,envytools/envytools,kfractal/envytools,kfractal/envytools,grate-driver/envytools,envytools/envytools,hakzsam/envytools,hakzsam/envytools