nvfx: switch to rules-ng-ng register headers

nvfx: switch to rules-ng-ng register headers

This is the new register generation toolkit in use by nouveau.

As far as I know, this is the best register description toolkit in
existence, and you should use it too for your hardware :)

Thanks to Marcin Kościelnicki for inventing it and performing
invaluable reverse engineering work of nVidia chips.