The ornamental design for a displaypanel with icon, as shown and described.
FIG. 1 is a front view of display panel with icon showing our new design; and,
FIG. 2 is a front view of display panel with icon showing the design of FIG. 1 on a device.
The broken line showing of the remainder of the user interface and the remainder of the display panel is for environmental purposes only and forms no part of the claimed design.