The ornamental design for a stand for displaydevice, as shown and described.
1. Stand for display device
1.1 : Perspective
1.2 : Front
1.3 : Back
1.4 : Left
1.5 : Top
1.6 : Bottom
1.7 : Reference view
The broken lines depict portions of the stand for display device that form no part of the claimed design; reproduction 1.1 is a perspective view of the stand for display device; reproduction 1.2 is a front view thereof; reproduction 1.3 is a back view thereof; reproduction 1.4 is a left view thereof where the right view is a mirror image; reproduction 1.5 is a top view thereof; reproduction 1.6 is a bottom view thereof; reproduction 1.7 is a reference view thereof showing an example of the usage of the subject design in which the subject article is folded and then a display device is placed on the stand.