turnip: Simplify vertex buffer bindings.
We have some number of HW VB bindings, and we can just update the given bindings at CmdBindVertexBuffers time, rather than making a shadow set of bindings based on the pipeline.
We have some number of HW VB bindings, and we can just update the given bindings at CmdBindVertexBuffers time, rather than making a shadow set of bindings based on the pipeline.