camera_manager: Look up pipelines match list in configuration file

Let's add a configuration file item for the pipelines match list.

The configuration snippet:

  configuration:
    pipelines_match_list:
      - rkisp1
      - simple

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/camera_manager.cpp

@@ -111,14 +111,16 @@ void CameraManager::Private::createPipelineHandlers()
 	 * file and only fallback on environment variable or all handlers, if
 	 * there is no configuration file.
 	 */
-	const char *pipesList =
-		utils::secure_getenv("LIBCAMERA_PIPELINES_MATCH_LIST");
-	if (pipesList) {
+	const auto pipesList =
+		configuration().envListOption("LIBCAMERA_PIPELINES_MATCH_LIST",
+					      { "pipelines_match_list" },
+					      ",");
+	if (pipesList.has_value()) {
 		/*
 		 * When a list of preferred pipelines is defined, iterate
 		 * through the ordered list to match the enumerated devices.
 		 */
-		for (const auto &pipeName : utils::split(pipesList, ",")) {
+		for (const auto &pipeName : pipesList.value()) {
 			const PipelineHandlerFactoryBase *factory;
 			factory = PipelineHandlerFactoryBase::getFactoryByName(pipeName);
 			if (!factory)