Add optional pipe double banking support to the Host mode Class drivers.

Descriptor processing routines now pass around void pointers rather than uint8_t pointers, as their destination datatype is know well known -- they are just streams of bytes until they are cast to the correct destination type by DESCRIPTOR_CAST.

LUFA/Drivers/USB/Class/Host/CDC.c

@@ -35,7 +35,7 @@
 #include "CDC.h"
 
 uint8_t CDC_Host_ConfigurePipes(USB_ClassInfo_CDC_Host_t* const CDCInterfaceInfo, uint16_t ConfigDescriptorSize,
-                                uint8_t* ConfigDescriptorData)
+                                void* ConfigDescriptorData)
 {
 	uint8_t FoundEndpoints = 0;