Firmware download is quite different for different hardware. The SDIO and CF
cards have two flat files that need to be downloaded, whereas the USB driver
needs only one file, but with an internal structure.

The code that handles this (USB only) structured file is currently in fw.c.
This patch moves this code into if_usb.c. The remaining functions in fw.c
have not much to do with firmware, they are various card- and network-stack
initialisation functions. I've moved them into main.c.
Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>