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/qmultimedia_common/mockmediaserviceprovider.h

@@ -63,7 +63,7 @@ public:
     {
         if (deleteServiceOnRelease) {
             delete service;
-            service = 0;
+            this->service = 0;
         }
     }