fix(mdns): reference protocol_examples_common from IDF

This makes the example project usable from the component registry

Author: igrr

components/mdns/examples/CMakeLists.txt

@@ -2,9 +2,5 @@
 # in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.5)
 
-set(EXTRA_COMPONENT_DIRS "..")
-# This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.
-list(APPEND EXTRA_COMPONENT_DIRS "../../../common_components/protocol_examples_common")
-
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(mdns_test)

components/mdns/examples/main/idf_component.yml

@@ -3,3 +3,5 @@ dependencies:
   idf: ">=5.0"
   espressif/mdns:
     version: "^1.0.0"
+  protocol_examples_common:
+    path: ${IDF_PATH}/examples/common_components/protocol_examples_common