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>

src/intel/vulkan/anv_private.h

@@ -3322,13 +3322,12 @@ struct anv_graphics_pipeline {
 
    struct anv_dynamic_state                     non_dynamic_state;
 
-   uint32_t                                     topology;
-
    /* These fields are required with dynamic primitive topology,
     * rasterization_samples used only with gen < 8.
     */
    VkLineRasterizationModeEXT                   line_mode;
    VkPolygonMode                                polygon_mode;
+   uint32_t                                     patch_control_points;
    uint32_t                                     rasterization_samples;
 
    VkColorComponentFlags                        color_comp_writes[MAX_RTS];