move HAL and tests folder

src/fsfw_hal/linux/CMakeLists.txt

@@ -0,0 +1,25 @@
+if(FSFW_HAL_ADD_RASPBERRY_PI)
+    add_subdirectory(rpi)
+endif()
+
+target_sources(${LIB_FSFW_NAME} PRIVATE
+	UnixFileGuard.cpp
+	CommandExecutor.cpp
+	utility.cpp
+)
+
+if(FSFW_HAL_LINUX_ADD_PERIPHERAL_DRIVERS)
+if(FSFW_HAL_LINUX_ADD_LIBGPIOD)
+	add_subdirectory(gpio)
+endif()
+	add_subdirectory(uart)
+	# Adding those does not really make sense on Apple systems which
+	# are generally host systems. It won't even compile as the headers
+	# are missing
+	if(NOT APPLE)
+		add_subdirectory(i2c)
+		add_subdirectory(spi)
+	endif()
+endif()
+
+add_subdirectory(uio)