nv30: import new driver for GeForce FX/6/7 chipsets, and Quadro variants

nv30: import new driver for GeForce FX/6/7 chipsets, and Quadro variants

The primary motivation for this rewrite was to have a maintainable driver
going forward, as nvfx was quite horrible in a lot of ways.

The driver is heavily based on the design of the nv50/nvc0 3d drivers we
already have, and uses the same common buffer/fence code.  It also passes
a HEAP more piglit tests than nvfx did, supports a couple more features,
and a few more to come still probably.

The CPU footprint of this driver is far far less than nvfx, and translates
into far greater framerates in a lot of applications (unless you're using
a CPU that's way way newer than the GPUs of these generations....)

Basically, we once again have a maintained driver for these chipsets \o/

Feel free to report bugs now!