fixed samples compilation

samples/gpu/bgfg_segm.cpp

@@ -6,6 +6,12 @@
 #include "opencv2/gpu.hpp"
 #include "opencv2/highgui.hpp"
 
+#include "opencv2/opencv_modules.hpp"
+
+#ifdef HAVE_OPENCV_NONFREE
+#  include "opencv2/nonfree/gpu.hpp"
+#endif
+
 using namespace std;
 using namespace cv;
 using namespace cv::gpu;

samples/gpu/cascadeclassifier_nvidia_api.cpp

@@ -8,6 +8,7 @@
 #include <cstdio>
 #include "opencv2/gpu/gpu.hpp"
 #include "opencv2/highgui/highgui.hpp"
+#include "opencv2/objdetect/objdetect.hpp"
 #include "opencv2/objdetect/objdetect_c.h"
 
 #ifdef HAVE_CUDA

samples/gpu/hog.cpp

@@ -7,6 +7,7 @@
 #include <opencv2/core/utility.hpp>
 #include "opencv2/gpu.hpp"
 #include "opencv2/highgui.hpp"
+#include "opencv2/objdetect.hpp"
 
 using namespace std;
 using namespace cv;