Leddevice refactoring the next part (#253)

* add general switchOff

* refactoring of leddevices regarding ledcount and switchoff

* remove obsolete includes

libsrc/leddevice/LedDeviceTpm2.h

@@ -1,8 +1,5 @@
 #pragma once
 
-// STL includes
-#include <string>
-
 // hyperion incluse
 #include "ProviderRs232.h"
 
@@ -22,6 +19,7 @@ public:
 	/// constructs leddevice
 	static LedDevice* construct(const Json::Value &deviceConfig);
 
+private:
 	///
 	/// Writes the led color values to the led-device
 	///
@@ -29,7 +27,4 @@ public:
 	/// @return Zero on succes else negative
 	///
 	virtual int write(const std::vector<ColorRgb> &ledValues);
-
-	/// Switch the leds off
-	virtual int switchOff();
 };