esp32: disable stack protector for startup code (CMake)

Files where stack protector is initialized should not be compiled with
stack protector enabled. This was done for Make but missing for CMake.

Fixes https://github.com/espressif/esp-idf/issues/2990.

components/esp32/CMakeLists.txt

@@ -142,4 +142,9 @@ else()
 
     endif()
 
+    # disable stack protection in files which are involved in initialization of that feature
+    set_source_files_properties(
+        stack_check.c cpu_start.c
+        PROPERTIES COMPILE_FLAGS
+        -fno-stack-protector)
 endif()