i965: Use brw.vue_map_geom_out instead of VS output VUE map where appropriate.

i965: Use brw.vue_map_geom_out instead of VS output VUE map where appropriate.

This patch modifies post-GS pipeline stages (transform feedback, clip,
sf, fs) to refer to the VUE map through brw->vue_map_geom_out rather
than brw->vs.prog_data->vue_map.  This ensures that when geometry
shader support is added, these pipeline stages will consult the
geometry shader output VUE map when appropriate, rather than the
vertex shader output VUE map.

v2: Fixed some stale "CACHE_NEW_VS_PROG" comments.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>