iris: Move VS draw parameter dirty flagging to iris_bind_vs_state

iris: Move VS draw parameter dirty flagging to iris_bind_vs_state

Now that we're looking at shader info system values rather than
vs_prog_data, there's no reason we have to do this when updating
the shader variants.  We can simply check it when binding a new
shader from the API point of view.

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8759>