can: SJA1000 generic platform bus driver

This driver adds support for the SJA1000 chips connected to the
"platform bus", which can be found on various embedded systems.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>