EGL: Set EGL_NO_X11 macro if --disable-x11 is used.
This is a follow-on to !192 (merged). This changes the --disable-x11 option to set the new EGL_NO_X11 macro, so that the EGL header files don't try to use the Xlib headers.
This is a follow-on to !192 (merged). This changes the --disable-x11 option to set the new EGL_NO_X11 macro, so that the EGL header files don't try to use the Xlib headers.