llvmpipe: (trivial) enable cube map arrays

The code is all in place now so enable it.
Seems to pass all relevant piglit tests (just like cube maps, some of the
cube map array tests need GALLIVM_DEBUG=no_quad_lod,no_rho_approx)

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
diff --git a/docs/GL3.txt b/docs/GL3.txt
index 9727e87..56c4994 100644
--- a/docs/GL3.txt
+++ b/docs/GL3.txt
@@ -114,7 +114,7 @@
   GL_ARB_shader_subroutine                             not started
   GL_ARB_tessellation_shader                           started (Chris, Ilia)
   GL_ARB_texture_buffer_object_rgb32                   DONE (i965, nvc0, r600, radeonsi, llvmpipe, softpipe)
-  GL_ARB_texture_cube_map_array                        DONE (i965, nv50, nvc0, r600, radeonsi, softpipe)
+  GL_ARB_texture_cube_map_array                        DONE (i965, nv50, nvc0, r600, radeonsi, llvmpipe, softpipe)
   GL_ARB_texture_gather                                DONE (i965, nv50, nvc0, r600, radeonsi)
   GL_ARB_texture_query_lod                             DONE (i965, nv50, nvc0, r600, radeonsi)
   GL_ARB_transform_feedback2                           DONE (i965, nv50, nvc0, r600, radeonsi)