Introduce enum / define for multiple devices

src/drivers/device/device.h

@@ -510,6 +510,9 @@ private:
 } // namespace device
 
 // class instance for primary driver of each class
-#define CLASS_DEVICE_PRIMARY 0
+enum CLASS_DEVICE {
+	CLASS_DEVICE_PRIMARY=0,
+	CLASS_DEVICE_SECONDARY=1
+};
 
 #endif /* _DEVICE_DEVICE_H */