can: ifi: Add IFI CANFD IP support

The patch adds support for IFI CAN/FD controller [1]. This driver
currently supports sending and receiving both standard CAN and new
CAN/FD frames. Both ISO and BOSCH variant of CAN/FD is supported.

[1] http://www.ifi-pld.de/IP/CANFD/canfd.html

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>