docs: Add missing release notes for ARB_separate_shader_objects

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reported-by: Ilia Mirkin <imirkin@alum.mit.edu>
diff --git a/docs/GL3.txt b/docs/GL3.txt
index 29075e8..55906f2 100644
--- a/docs/GL3.txt
+++ b/docs/GL3.txt
@@ -129,7 +129,7 @@
   GLSL 4.1                                             not started
   GL_ARB_ES2_compatibility                             DONE (i965, nv50, nvc0, r300, r600, radeonsi)
   GL_ARB_get_program_binary                            DONE (0 binary formats)
-  GL_ARB_separate_shader_objects                       started (Ian Romanick, Gregory Hainaut)
+  GL_ARB_separate_shader_objects                       DONE (all drivers)
   GL_ARB_shader_precision                              not started
   GL_ARB_vertex_attrib_64bit                           not started
   GL_ARB_viewport_array                                DONE (i965, nv50, r600)