1. Open your picture
2. Add a new empty layer and select the gradient tool (G)
Use the white to black Radial Gradient and drag a layer form the center to the outside. Probably you must to it a couple of times to get it on the right position.
3. Change the layer Blending mode to Overlay or Soft light.
4. Reduce the layers Opacity.
For this image we reduced the opacity to 35%