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/ioUringAssemblyEngine.h

@@ -36,10 +36,6 @@ public:
 	bool setup();
 	void finalize();
 
-	typedef std::function<void(void*, int)> resetAndAssembleFrameCbFn;
-	void resetAndAssembleFrame(resetAndAssembleFrameCbFn onCqeReady);
-	void stop(bool doAcquireLock = true);
-
 	typedef std::function<void(bool, AsynchronousLoop)> assembleFrameReqCbFn;
 	void assembleFrameReq(Callback<assembleFrameReqCbFn> cb);
 
@@ -50,6 +46,11 @@ public:
 	static bool compactionIsNeeded(uint32_t nSucceeded, uint32_t nTotal)
 		{ return nSucceeded != 0 && nTotal != 0 && nSucceeded != nTotal; }
 
+private:
+	typedef std::function<void(void*, int)> resetAndAssembleFrameCbFn;
+	void resetAndAssembleFrame(resetAndAssembleFrameCbFn onCqeReady);
+	void stop(bool doAcquireLock = true);
+
 private:
 	PcloudStimulusBuffer& parent;