Fix button type to update coordinates when dragging

A move position (x,y) can be delivered to the MouseArea only if
button is Qt::NoButton during mouse move (dragging). Otherwise
mouse move does not cause positionChanged in MouseArea.

Task-number: QTBUG-95453
Change-Id: I298943dc4f6f30714e940f4029c62dd52c176b93
Reviewed-by: Jaeyoon Jung <jaeyoon.jung@lge.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
(cherry picked from commit 3727683bd5f57666926603b84bccdf24d3839c98)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp

@@ -204,6 +204,9 @@ void QEvdevMouseHandler::sendMouseEvent()
         m_prevInvalid = false;
     }
 
+    if (m_eventType == QEvent::MouseMove)
+        emit handleMouseEvent(x, y, m_abs, m_buttons, Qt::NoButton, m_eventType);
+    else
         emit handleMouseEvent(x, y, m_abs, m_buttons, m_button, m_eventType);
 
     m_prevx = m_x;