docs: Update status of ARB_conditional_render_inverted

Done for: nvc0, softpipe and llvmpipe

Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
2 files changed