removed HK switch helper from cmake file

src/fsfw/datapool/CMakeLists.txt

@@ -1,6 +1,4 @@
-target_sources(${LIB_FSFW_NAME} 
+target_sources(${LIB_FSFW_NAME} PRIVATE 
-	PRIVATE 
+    PoolDataSetBase.cpp
-		HkSwitchHelper.cpp
+    PoolEntry.cpp
-		PoolDataSetBase.cpp
-		PoolEntry.cpp
 )