Fill in serial field for all HID controllers using hidapi

Controllers/LogitechController/RGBController_LogitechG213.cpp

@@ -37,6 +37,7 @@ RGBController_LogitechG213::RGBController_LogitechG213(LogitechG213Controller* l
     type        = DEVICE_TYPE_KEYBOARD;
     description = "Logitech G213 Keyboard Device";
     location    = logitechG213->GetDeviceLocation();
+    serial      = logitechG213->GetSerialString();
 
     mode Direct;
     Direct.name                     = "Direct";