CDC Ethernet + CDC Serial + Storage configuration

configname: CONFIG_USB_G_MULTI_CDC

USB Gadget Drivers
└─>CDC Ethernet + CDC Serial + Storage configuration
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
This option enables a configuration with CDC Ethernet (ECM), CDC
Serial and Mass Storage functions available in the Multifunction
Composite Gadget.

If unsure, say "y".