can: cc770: add platform bus driver for the CC770 and AN82527

This driver works with both, static platform data and device tree
bindings. It has been tested on a TQM855L board with two AN82527
CAN controllers on the local bus.

CC: Devicetree-discuss@lists.ozlabs.org
CC: linuxppc-dev@ozlabs.org
CC: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>