The ornamental design for a doorbell faceplate, as shown and described.
FIG. 1 is a front view of a doorbell faceplate; and,
FIG. 2 is a side view of a doorbell faceplate.
The portion of the broken line in FIG. 2 immediately adjacent the shaded area defines the bounds of the claimed design; the rest of the broken line is for illustrative purpose only. None of the broken lines form a part of the claim.