documentation updates ...

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

list: remove duplicated list.h ...

We accidently have two list implementations in the tree:
include/list.h and include/linux/list.h. This patch moves
the latter (newer one) to include/linux/list.h.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add USB device support ...

This patch adds support for USB devices. It uses
the Linux Kernel gadget API. Along with this patch
comes driver support for the Freescale (arc) USB OTG
Core and USB Device Firmware Update (DFU)
The serial gadget support is not working at the moment.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>