staging: ft1000: Merge common definitions from USB and PCMCIA drivers

Merge common definitions from ft1000-usb and ft1000-pcmcia drivers to
a common ft1000.h file.
This revealed two odd things in ft1000-usb which might be bugs so add
comments about them to ft1000_usb.h.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>