radeonsi: set GS_STATE_OUTPRIM and PROVOKING_VTX_INDEX only when they change

radeonsi: set GS_STATE_OUTPRIM and PROVOKING_VTX_INDEX only when they change

This moves setting those registers from an unconditional place in draw_vbo
into si_set_rasterized_prim (for draw_vbo), si_update_rasterized_prim
(for bind_xx_shader), and si_bind_rs_state.

It's a little more complicated than expected.

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18195>