QAccessibleInterface: move implementation beside doc block

Adjust doc text to what's used elsewhere in QAccessible.

Change-Id: I8bd194e55374b8258361ae254817a4298c4fa3dc
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

src/gui/accessible/qaccessible.cpp

@@ -443,10 +443,11 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \fn QAccessibleInterface::~QAccessibleInterface()
-
-    Destroys the object.
+    Destroys the QAccessibleInterface.
 */
+QAccessibleInterface::~QAccessibleInterface()
+{
+}
 
 /*!
     \typedef QAccessible::Id
@@ -1254,10 +1255,6 @@ QColor QAccessibleInterface::backgroundColor() const
     return QColor();
 }
 
-QAccessibleInterface::~QAccessibleInterface()
-{
-}
-
 /*!
     \fn QAccessibleTextInterface *QAccessibleInterface::textInterface()
 */