Allow our V4L2 to be used.

Index: src/gsttools/qgstutils.cpp
--- src/gsttools/qgstutils.cpp.orig
+++ src/gsttools/qgstutils.cpp
@@ -61,7 +61,11 @@ template<typename T, int N> static int lengthOf(const 
 
 #if QT_CONFIG(linux_v4l)
 #  include <private/qcore_unix_p.h>
-#  include <linux/videodev2.h>
+#  if defined(__OpenBSD__)
+#    include <sys/videoio.h>
+#  else
+#    include <linux/videodev2.h>
+#  endif
 #endif
 
 #include "qgstreamervideoinputdevicecontrol_p.h"