Modified cmake to use STACK_MAX and STACK_MAIN

cmake/common/px4_base.cmake

cmake/configs/nuttx_mindpx-v2_default.cmake

cmake/configs/nuttx_px4-stm32f4discovery_default.cmake

cmake/configs/nuttx_px4fmu-v1_default.cmake

cmake/configs/nuttx_px4fmu-v2_default.cmake

cmake/configs/nuttx_px4fmu-v2_ekf2.cmake

cmake/configs/nuttx_px4fmu-v4_default.cmake

cmake/configs/posix_sitl_default.cmake

cmake/configs/posix_sitl_ekf2.cmake

cmake/configs/posix_sitl_replay.cmake

cmake/nuttx/px4_impl_nuttx.cmake

cmake/qurt/px4_impl_qurt.cmake

src/drivers/ardrone_interface/CMakeLists.txt

src/drivers/bst/CMakeLists.txt

src/drivers/camera_trigger/CMakeLists.txt

src/drivers/ets_airspeed/CMakeLists.txt

src/drivers/frsky_telemetry/CMakeLists.txt

src/drivers/gimbal/CMakeLists.txt

src/drivers/gps/CMakeLists.txt

src/drivers/hmc5883/CMakeLists.txt