Right now the ActiveRender code in D3D8 requests a GLX_DEPTH_SIZE of
32 in case the direct3d color format also has a depth of 32. As
verified on various linux drivers (Ati fglrx, Ati (dri) and Nvidia)
the color depth needs to be 24. This patch sets the depth to 24 and it
fixes bugs in 3dmark2001 and other programs.