Seperate out the device demos and project's configuration descriptor structure definitions to clearly indicate what descriptors belong to which interface.

Demos/Device/LowLevel/VirtualSerial/Descriptors.h

@@ -65,11 +65,15 @@
 		typedef struct
 		{
 			USB_Descriptor_Configuration_Header_t    Config;
+
+			// CDC Control Interface
 			USB_Descriptor_Interface_t               CDC_CCI_Interface;
 			USB_CDC_Descriptor_FunctionalHeader_t    CDC_Functional_Header;
 			USB_CDC_Descriptor_FunctionalACM_t       CDC_Functional_ACM;
 			USB_CDC_Descriptor_FunctionalUnion_t     CDC_Functional_Union;
 			USB_Descriptor_Endpoint_t                CDC_NotificationEndpoint;
+
+			// CDC Data Interface
 			USB_Descriptor_Interface_t               CDC_DCI_Interface;
 			USB_Descriptor_Endpoint_t                CDC_DataOutEndpoint;
 			USB_Descriptor_Endpoint_t                CDC_DataInEndpoint;