cmake: revert using EXCLUDE_FROM_ALL when adding component subdirectories

Reverting (for now) the change in !4452 to use EXCLUDE_FROM_ALL.
Apparently this also affects custom targets with ALL option specified,
not causing them to be built with the project.

This is apparently a bug which has a merged fix:
https://gitlab.kitware.com/cmake/cmake/merge_requests/2816

CMakeLists.txt

@@ -74,9 +74,9 @@ foreach(component_target ${build_component_targets})
     idf_build_get_property(build_prefix __PREFIX)
     set(__idf_component_context 1)
     if(NOT prefix STREQUAL build_prefix)
-        add_subdirectory(${dir} ${prefix}_${_name} EXCLUDE_FROM_ALL)
+        add_subdirectory(${dir} ${prefix}_${_name})
     else()
-        add_subdirectory(${dir} ${_name} EXCLUDE_FROM_ALL)
+        add_subdirectory(${dir} ${_name})
     endif()
     set(__idf_component_context 0)
 endforeach()