MAINTAINERS: add Marc Kleine-Budde as co maintainer for CAN networking layer

This patch adds Marc Kleine-Budde as a co maintainer for the CAN networking
layer.

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

MAINTAINERS

@@ -2369,6 +2369,7 @@ F:	arch/x86/include/asm/tce.h
 
 CAN NETWORK LAYER
 M:	Oliver Hartkopp <socketcan@hartkopp.net>
+M:	Marc Kleine-Budde <mkl@pengutronix.de>
 L:	linux-can@vger.kernel.org
 W:	https://github.com/linux-can
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git