Remove unused cmake boost variables

Author: cybaol

cmake/pcl_find_boost.cmake

@@ -34,10 +34,6 @@ endif()
 find_package(Boost 1.65.0 QUIET COMPONENTS ${BOOST_OPTIONAL_MODULES})
 find_package(Boost 1.65.0 REQUIRED COMPONENTS ${BOOST_REQUIRED_MODULES})
 
-if(Boost_SERIALIZATION_FOUND)
-  set(BOOST_SERIALIZATION_FOUND TRUE)
-endif()
-
 if(Boost_FOUND)
   set(BOOST_FOUND TRUE)
 endif()

cmake/pcl_pclconfig.cmake

@@ -92,9 +92,6 @@ endif()
 if(Boost_SERIALIZATION_FOUND)
   string(APPEND PCLCONFIG_AVAILABLE_BOOST_MODULES " serialization")
 endif()
-if(Boost_CHRONO_FOUND)
-  string(APPEND PCLCONFIG_AVAILABLE_BOOST_MODULES " chrono")
-endif()
 
 configure_file("${PCL_SOURCE_DIR}/PCLConfig.cmake.in"
                "${PCL_BINARY_DIR}/PCLConfig.cmake" @ONLY)