RTPS and micro-CDR build system cleanup (#8084)

CMakeLists.txt

cmake/common/px4_base.cmake

cmake/configs/nuttx_aerocore2_default.cmake

cmake/configs/nuttx_aerofc-v1_default.cmake

cmake/configs/nuttx_auav-x21_default.cmake

cmake/configs/nuttx_crazyflie_default.cmake

cmake/configs/nuttx_esc35-v1_default.cmake

cmake/configs/nuttx_mindpx-v2_default.cmake

cmake/configs/nuttx_nxphlite-v3_default.cmake

cmake/configs/nuttx_px4-same70xplained-v1_default.cmake

cmake/configs/nuttx_px4-stm32f4discovery_default.cmake

cmake/configs/nuttx_px4cannode-v1_default.cmake

cmake/configs/nuttx_px4esc-v1_default.cmake

cmake/configs/nuttx_px4fmu-v2_default.cmake

cmake/configs/nuttx_px4fmu-v2_test.cmake

cmake/configs/nuttx_px4fmu-v3_default.cmake

cmake/configs/nuttx_px4fmu-v4_default.cmake

cmake/configs/nuttx_px4fmu-v4pro_default.cmake

cmake/configs/nuttx_px4fmu-v5_default.cmake

cmake/configs/nuttx_px4io-v2_default.cmake