v3d: emit geometry shader state commands

v3d: emit geometry shader state commands

This is good enough to get basic GS workloads working, later patches will
improve this by adding instancing support, proper SIMD configuration, etc.

Notice that most of the TESSELLATION_GEOMETRY_SHADER_PARAMS fields are only
relevant when tessellation shaders are present. We do not support tessellation
yet, but we still need to fill in these tessellation state with default values
since our packing functions require some of these to have non-zero values.

v2:
 - Add a comment in the code explaining why we fill in
   tessellation fields (Alejandro)

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>