fix #5985 CLion exporter results in cmake build directory, causes compiler to fail in unexpect...

Author: thinkberg

tools/export/cmake/CMakeLists.txt.tmpl

@@ -103,4 +103,7 @@ IF(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/project.cmake)
   INCLUDE(${CMAKE_CURRENT_SOURCE_DIR}/project.cmake)
 ELSE()
   MESSAGE(STATUS "Add a local project.cmake file to add your own targets.")
-ENDIF()
+ENDIF()
+
+# this will take care of binary directories generated by cmake/clion not to confuse the cli build
+FILE(GENERATE OUTPUT "${CMAKE_BINARY_DIR}/.mbedignore" CONTENT "*")