can: add support of SAE J1939 protocol

SAE J1939 is the vehicle bus recommended practice used for communication
and diagnostics among vehicle components. Originating in the car and
heavy-duty truck industry in the United States, it is now widely used in
other parts of the world.

J1939, ISO 11783 and NMEA 2000 all share the same high level protocol.
SAE J1939 can be considered the replacement for the older SAE J1708 and
SAE J1587 specifications.

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Elenita Hinds <ecathinds@gmail.com>
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Maxime Jayat <maxime.jayat@mobile-devices.fr>
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Author: The j1939 authors

Documentation/networking/index.rst

@@ -17,6 +17,7 @@ Contents:
    devlink-trap
    devlink-trap-netdevsim
    ieee802154
+   j1939
    kapi
    z8530book
    msg_zerocopy