Repair V4L backend

modules/videoio/src/videoio_registry.cpp

@@ -84,6 +84,8 @@ static const struct VideoBackendInfo builtin_backends[] =
     DECLARE_BACKEND(CAP_V4L2, "V4L2", MODE_CAPTURE_ALL),
 #elif defined HAVE_CAMV4L
     DECLARE_BACKEND(CAP_V4L, "V4L", MODE_CAPTURE_ALL),
+#elif defined HAVE_VIDEOIO
+    DECLARE_BACKEND(CAP_V4L, "V4L_BSD", MODE_CAPTURE_ALL),
 #endif
 
 
@@ -433,6 +435,11 @@ void VideoCapture_create(CvCapture*& capture, Ptr<IVideoCapture>& icap, VideoCap
     case CAP_GPHOTO2:
         TRY_OPEN(createGPhoto2Capture(index));
         break;
+#endif
+#if defined HAVE_CAMV4L || defined HAVE_CAMV4L2 || defined HAVE_VIDEOIO
+    case CAP_V4L:
+        TRY_OPEN_LEGACY(cvCreateCameraCapture_V4L(index))
+        break;
 #endif
     case CAP_FIREWIRE:
 #ifdef HAVE_DC1394_2