MAINTAINERS: Add separate section for USB NETWORKING DRIVERS

There are several drivers in drivers/net/usb/ that
do not have specific MAINTAINERS that should have
emails forwarded to the linux-usb mailing list.

Add a section for those drivers.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -8664,6 +8664,11 @@ T:	git git://git.alsa-project.org/alsa-kernel.git
 S:	Maintained
 F:	sound/usb/midi.*
 
+USB NETWORKING DRIVERS
+L:	linux-usb@vger.kernel.org
+S:	Odd Fixes
+F:	drivers/net/usb/
+
 USB OHCI DRIVER
 M:	Alan Stern <stern@rowland.harvard.edu>
 L:	linux-usb@vger.kernel.org