usb: gadget: Add snapshot of USB QDSS function driver

This change adds the USB QDSS function driver which allows
communication of QDSS trace/debug functionality over USB.
This snapshot is taken as of commit 29e6452e14b6 ("net: rmnet_data:
Fix comments on code review").

Add missing MODULE_LICENSE to f_qdss.c as well.

Change-Id: If56e93ebd7a7f83a54d917eba0c4f105a24a0cdc
Signed-off-by: Jack Pham <jackp@codeaurora.org>