MAINTAINERS: add include/dt-bindings/net to NETWORKING DRIVERS

Maintainers of the directory Documentation/devicetree/bindings/net
are also the maintainers of the corresponding directory
include/dt-bindings/net.

Add the file entry for include/dt-bindings/net to the appropriate
section in MAINTAINERS.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220613121826.11484-1-lukas.bulwahn@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

MAINTAINERS

@@ -13799,6 +13799,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
 F:	Documentation/devicetree/bindings/net/
 F:	drivers/connector/
 F:	drivers/net/
+F:	include/dt-bindings/net/
 F:	include/linux/etherdevice.h
 F:	include/linux/fcdevice.h
 F:	include/linux/fddidevice.h