cmake: enable --ethernet to generate common param metadata

This will add the MAV_x_BROADCAST params.

cmake/metadata.cmake

@@ -50,7 +50,7 @@ file(GLOB_RECURSE yaml_config_files ${PX4_SOURCE_DIR}/src/modules/*.yaml
 add_custom_target(metadata_parameters
 	COMMAND ${CMAKE_COMMAND} -E make_directory ${PX4_BINARY_DIR}/docs
 	COMMAND ${PYTHON_EXECUTABLE}
-	${PX4_SOURCE_DIR}/Tools/serial/generate_config.py --all-ports --params-file ${PX4_SOURCE_DIR}/src/generated_serial_params.c --config-files ${yaml_config_files}
+	${PX4_SOURCE_DIR}/Tools/serial/generate_config.py --all-ports --ethernet --params-file ${PX4_SOURCE_DIR}/src/generated_serial_params.c --config-files ${yaml_config_files}
 	COMMAND ${PYTHON_EXECUTABLE} ${PX4_SOURCE_DIR}/src/lib/parameters/px_process_params.py
 		--src-path `find ${PX4_SOURCE_DIR}/src -maxdepth 4 -type d`
 		--inject-xml ${PX4_SOURCE_DIR}/src/lib/parameters/parameters_injected.xml