Removed QMediaServiceProvider parameter from media objects constructors.

QMediaServiceProvider should be removed from the public API,
to provide media objects with a custom media service.

A protected QMediaPlayer/QCamera/QRadioTuner/etc constructor
with QMediaService* parameter is a cleaner and more
flexible solution.

Change-Id: I335cce4bbebe0e548c3df338f206e7be7c93c3dd
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>
Reviewed-by: Jonas Rabbe <jonas.rabbe@nokia.com>

tests/auto/unit/qcameraviewfinder/tst_qcameraviewfinder.cpp

@@ -74,8 +74,9 @@ void tst_QCameraViewFinder::initTestCase()
     provider = new MockMediaServiceProvider;
     mockcameraservice = new MockCameraService;
     provider->service = mockcameraservice;
+    QMediaServiceProvider::setDefaultServiceProvider(provider);
 
-    camera = new QCamera(0, provider);
+    camera = new QCamera;
     viewFinder = new QCameraViewfinder();
 }