mobile: add qmlprefs class

add class to cmake and pro
register class

Signed-off-by: Jan Iversen <jani@apache.org>

mobile-widgets/qmlprefs.h

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef QMLPREFS_H
+#define QMLPREFS_H
+
+#include <QObject>
+
+
+class QMLPrefs : public QObject {
+	Q_OBJECT
+
+public:
+	QMLPrefs();
+	~QMLPrefs();
+
+	static QMLPrefs *instance();
+
+public slots:
+
+private:
+	static QMLPrefs *m_instance;
+
+signals:
+};
+
+#endif