cmake: make main a component again

* Original commit: espressif/esp-idf@d9939ce

Author: renzbagaporo

components/mdns/CMakeLists.txt

@@ -1,4 +1,6 @@
-set(COMPONENT_SRCDIRS ".")
+set(COMPONENT_SRCS "mdns.c"
+                   "mdns_console.c"
+                   "mdns_networking.c")
 set(COMPONENT_ADD_INCLUDEDIRS "include")
 set(COMPONENT_PRIV_INCLUDEDIRS "private_include")
 set(COMPONENT_REQUIRES lwip mbedtls console tcpip_adapter)

examples/protocols/mdns/CMakeLists.txt

@@ -1,8 +1,6 @@
-# The following four lines of boilerplate have to be in your project's CMakeLists
+# The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.5)
 
-set(MAIN_SRCS main/mdns_example_main.c)
-
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(mdns-test)

examples/protocols/mdns/main/CMakeLists.txt

@@ -0,0 +1,4 @@
+set(COMPONENT_SRCS "mdns_example_main.c")
+set(COMPONENT_ADD_INCLUDEDIRS ".")
+
+register_component()