egl_dri2: Enable image extensions in one place

We know what we can support in egl_dri2.c so just enable the extensions
there.
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index f7e063b..e5dee55 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -462,6 +462,13 @@
       }
    }
 
+   if (dri2_dpy->image) {
+      disp->Extensions.MESA_drm_image = EGL_TRUE;
+      disp->Extensions.KHR_image_base = EGL_TRUE;
+      disp->Extensions.KHR_gl_renderbuffer_image = EGL_TRUE;
+      disp->Extensions.KHR_gl_texture_2D_image = EGL_TRUE;
+   }
+
    return EGL_TRUE;
 
  cleanup_dri_screen: