Fixing some doc errors for overview

Change-Id: Ic502abf295d402678bb28e68bfacc76ae05ee8ec
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>

src/multimedia/audio/qaudioprobe.cpp

@@ -44,7 +44,7 @@
     \inmodule QtMultimedia
 
     \ingroup multimedia
-    \ingroup multimedia_video
+    \ingroup multimedia_audio
 
     \brief The QAudioProbe class allows you to monitor audio being played or recorded.
 

src/multimedia/camera/qcamerafocus.cpp

@@ -281,7 +281,8 @@ void QCameraFocusZone::setStatus(QCameraFocusZone::FocusZoneStatus status)
     \brief The QCameraFocus class provides an interface for focus and zoom related camera settings.
 
     \inmodule QtMultimedia
-    \ingroup camera
+    \ingroup multimedia
+    \ingroup multimedia_camera
 
     On hardware that supports it, this class lets you adjust the focus
     or zoom (both optical and digital).  This also includes things

src/multimedia/recording/qmediaencodersettings.cpp

@@ -415,6 +415,10 @@ private:
 
     \brief The QVideoEncoderSettings class provides a set of video encoder settings.
 
+    \inmodule QtMultimedia
+    \ingroup multimedia
+    \ingroup multimedia_recording
+
     A video encoder settings object is used to specify the video encoder
     settings used by QMediaRecorder.  Video encoder settings are selected by
     constructing a QVideoEncoderSettings object, setting the desired properties
@@ -737,6 +741,10 @@ private:
     \brief The QImageEncoderSettings class provides a set of image encoder
     settings.
 
+    \inmodule QtMultimedia
+    \ingroup multimedia
+    \ingroup multimedia_camera
+
     A image encoder settings object is used to specify the image encoder
     settings used by QCameraImageCapture.  Image encoder settings are selected
     by constructing a QImageEncoderSettings object, setting the desired