cmake HAVE_CAMV4L examples

chsl/PLADE code/3rd_party/opencv/cmake/OpenCVFindLibsVideo.cmake :165

CHECK_INCLUDE_FILE(linux/videodev.h HAVE_CAMV4L)

plumonito/dtslam 3rdparty/opencv-git/cmake/OpenCVFindLibsVideo.cmake :159

CHECK_INCLUDE_FILE(linux/videodev.h HAVE_CAMV4L)

plumonito/dtslam 3rdparty/opencv-git/modules/videoio/CMakeLists.txt :74

elseif(HAVE_CAMV4L OR HAVE_CAMV4L2 OR HAVE_VIDEOIO)