MAINTAINERS: Add file patterns for can device tree bindings

Submitters of device tree binding documentation may forget to CC
the subsystem maintainer if this is missing.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

MAINTAINERS

@@ -2814,6 +2814,7 @@ W:	https://github.com/linux-can
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git
 S:	Maintained
+F:	Documentation/devicetree/bindings/net/can/
 F:	drivers/net/can/
 F:	include/linux/can/dev.h
 F:	include/linux/can/platform/