Do not handle ScreenEdges::check for Edges which don't activate for Pointer

Summary:
On X11 the edges reserved only for pointer started to show the approach
geometry. This problem is addressed by this change.

Touch screen events do not go through this method, neither is it used on
Wayland.

Test Plan: Tested on X11, problem fixed

Reviewers: KWin, Plasma

Subscribers: plasma-devel, kwin

Tags: KWin

Differential Revision: https://phabricator.kde.org/D5421