videoio(v4l): fix build due missing defines

- V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT
- V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH

modules/videoio/src/cap_v4l.cpp

@@ -243,6 +243,14 @@ make & enjoy!
 #define V4L2_CID_ISO_SENSITIVITY (V4L2_CID_CAMERA_CLASS_BASE+23)
 #endif
 
+// https://github.com/opencv/opencv/issues/13929
+#ifndef V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT
+#define V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT (V4L2_CID_MPEG_BASE+364)
+#endif
+#ifndef V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH
+#define V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH (V4L2_CID_MPEG_BASE+365)
+#endif
+
 /* Defaults - If your board can do better, set it here.  Set for the most common type inputs. */
 #define DEFAULT_V4L_WIDTH  640
 #define DEFAULT_V4L_HEIGHT 480