The ornamental design for a ceiling panel surface pattern, as shown and described.
FIG. 1 is a perspective view;
FIG. 2 is a top plan view thereof;
FIG. 3 is a perspective view of a second embodiment; and,
FIG. 4 is a top plan view thereof.
The bottom, front, back and sides of the ceiling panel are shown in broken lines for illustrative purposes only and form no part of the claimed design.