can: peak_usb_fd: add support for ISO / non-ISO mode switching

The PCAN USB (pro) FD adapters with firmware versions > 2.x support the
switching between ISO (default) and non-ISO conform bitstreams on the CAN bus.
The setting for the 2.x firmware adapters can be modified with the 'ip' tool
from the iproute2 package (option: fd-non-iso [on|off]).

Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>