asio coap: If LWIP IPV6 is disabled, automatically don't build asio & coap

- Removes need to manually exclude these components as shown at
  https://github.com/espressif/esp-idf/issues/3781#issuecomment-825742378

- Hide the config for these components if IPV6 is disabled

- The components are still included in the build, but with no source
  files


* Original commit: espressif/esp-idf@e305f29382

components/asio/CMakeLists.txt

@@ -1,3 +1,11 @@
+if(NOT CONFIG_LWIP_IPV6 AND NOT CMAKE_BUILD_EARLY_EXPANSION)
+    # note: the component is still included in the build so it can become visible again in config
+    # without needing to re-run CMake. However no source or header files are built.
+    message(STATUS "IPV6 support is disabled so the asio component will not be built")
+    idf_component_register()
+    return()
+endif()
+
 set(asio_sources "asio/asio/src/asio.cpp")
 
 if(CONFIG_ASIO_SSL_SUPPORT)