b43-fwcutter: new package

b43-fwcutter is an open-source tool (BSD-2c) that extracts the
firmwares from the Broadcom proprietary drivers. Those firmwares can
then be used by the open-source b43 and b43-legacy drivers of the
Linux kernel.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>