mesa: don't update draw buffer bounds in _mesa_update_state

mesa: don't update draw buffer bounds in _mesa_update_state

st/mesa doesn't need the draw bounds for draw calls. I've added the call
where it's necessary in core Mesa and drivers, but I suspect that most
drivers can just move the call to the right places.

The core Mesa places aren't hot paths, so the call overhead doesn't matter
there.

For now, only st/mesa is made such that this function is invoked very
rarely.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>