Use make step base for qmake projects

There are two differences that get introduced by this change:
- The configuration widget checks that there is a build configuration,
  but not if this build configuration is a QmakeBuildConfiguration. This
  should not matter, since Qmake is still the only supported project
  type for the qmake specific make step
- It removes the automaticallyAddedArguments(). As far as I can see this
  never had any effect anyhow, though. They were never actually added to
  the arguments.

Change-Id: I73be227a32117e462def38bdd040dbd7cbcc113f
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/qmakeprojectmanager/qmakeprojectmanagerplugin.cpp

@@ -95,7 +95,7 @@ public:
         qmakeProjectWizard{"qmakeproject", IWizardFactory::ProjectWizard};
 
     QMakeStepFactory qmakeStepFactory;
-    MakeStepFactory makeStepFactory;
+    QmakeMakeStepFactory makeStepFactory;
 
     QmakeBuildConfigurationFactory buildConfigFactory;
     DesktopQmakeRunConfigurationFactory runConfigFactory;