Fix incorrect documentation for QWaylandInputDevice

A QWaylandInputDevice is not actually an input device, but a group of
keyboards, pointer and touch devices.

Change-Id: Ib22f8cc71670cf83c70798d9eb24d48a04398b22
Reviewed-by: Venugopal Shivashankar <Venugopal.Shivashankar@qt.io>

src/compositor/compositor_api/qwaylandinput.cpp

@@ -152,7 +152,7 @@ QWaylandKeymap::QWaylandKeymap(const QString &layout, const QString &variant, co
  * \class QWaylandInputDevice
  * \inmodule QtWaylandCompositor
  * \preliminary
- * \brief The QWaylandInputDevice class represents an input device such as a keyboard, mouse, and touch input.
+ * \brief The QWaylandInputDevice class provides access to keyboard, mouse, and touch input.
  *
  * The QWaylandInputDevice provides access to different types of user input and maintains
  * a keyboard focus and a mouse pointer. It corresponds to the wl_seat interface in the Wayland protocol.