r300g: merge VS output mapping state (VAP) to rasterizer block state (RS)

r300g: merge VS output mapping state (VAP) to rasterizer block state (RS)

These two should be tied together because what's set in VAP or stuffed in GA
should be rasterized in RS. Not doing so causes a hardlock.

The reason for the merge is that if stuffed texture coordinates (e.g. point
sprite texgen) happen to occupy the texcoord slot dedicated to fog or wpos,
the two must be relocated to other free slots, which needs remapping the vertex
shader outputs.

The rasterizer code is now literally a sequence read-rasterize-write.