anv: Rework setting primitive topology

anv: Rework setting primitive topology

For one thing, we were deceptively setting it wrong in genX_cmd_buffer.c
and then overwriting it in each of of gfx7_cmd_buffer.c and
gfx8_cmd_buffer.c.  Pull it all into genX_cmd_buffer.c so it's no longer
duplicated.  Also, stop doing the PATCHLIST conversion in anv_pipeline.c
and just store the number of patch vertices.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17564>