IoUringAssmEngn,OClCollMeshEngn: start/stop aren't public iface

Placing these functions in the public section kind of conceptually
confuses the reader since start/stop are indeed public interface
members in StimulusBuffer -- but they're not in the member objects.

stimBuffApis/livoxGen1/openClCollatingAndMeshingEngine.h

@@ -41,11 +41,16 @@ public:
 	bool setup();
 	void finalize();
 
+	typedef std::function<void(bool, StimulusFrame&)>
+		compactCollateAndMeshFrameReqCbFn;
+	void compactCollateAndMeshFrameReq(
+		AsynchronousLoop& asyncLoop, StimulusFrame& stimulusFrame,
+		Callback<compactCollateAndMeshFrameReqCbFn> callback);
+
+private:
 	// Callback function types
 	typedef std::function<void(cl_int)> compactKernelCbFn;
 	typedef std::function<void(cl_int)> collateKernelCbFn;
-	typedef std::function<void(bool, StimulusFrame&)>
-		compactCollateAndMeshFrameReqCbFn;
 
 	bool startCompactKernel(
 		StagingBuffer& assemblyBuff, uint32_t nSucceeded,
@@ -58,10 +63,7 @@ public:
 	void stopCollateKernel();
 	void stop();
 
-	void compactCollateAndMeshFrameReq(
-		AsynchronousLoop& asyncLoop, StimulusFrame& stimulusFrame,
-		Callback<compactCollateAndMeshFrameReqCbFn> callback);
-
+public:
 	// Get kernel execution durations in milliseconds
 	std::chrono::milliseconds getCompactKernelDuration() const;
 	std::chrono::milliseconds getCollateKernelDuration() const;