qml: accept all devices in playback speed control wheel handler

By default `WheelHandler` only accepts mouse (unlike other handlers
where all devices are accepted by default), and it also does not
make use of synthesized mouse events. We can accept all devices
here, I don't see why we should limit the accepted devices here.

Currently on Wayland certain mouse types are not reported as
"mouse", this is a problem for the wheel functionality of the
playback speed control. Accepting all devices fixes this issue.

modules/gui/qt/player/qml/controlbarcontrols/PlaybackSpeedButton.qml

@@ -101,6 +101,8 @@ PopupIconToolButton {
         WheelHandler {
             orientation: Qt.Vertical | Qt.Horizontal
 
+            acceptedDevices: PointerDevice.AllDevices
+
             onWheel: (wheel) => {
                 if (!root.popup.contentItem || !root.popup.contentItem.slider) {
                     event.accepted = false