cmake tf2_ros examples

jkk-research/pointcloud_to_grid CMakeLists.txt :22 

find_package(tf2_ros REQUIRED)

ros/robot_state_publisher CMakeLists.txt :24 

find_package(tf2_ros REQUIRED)

SICKAG/sick_scan_xd CMakeLists.txt :337 

find_package(tf2_ros REQUIRED)

septentrio-gnss/septentrio_gnss_driver CMakeLists.txt :163 

find_package(tf2_ros REQUIRED)