9p: Add rest of 9p files to MAINTAINERS entry

It was missing net and include directories.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

MAINTAINERS

@@ -178,6 +178,11 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs.git
 S:	Maintained
 F:	Documentation/filesystems/9p.txt
 F:	fs/9p/
+F:	net/9p/
+F:	include/net/9p/
+F:	include/uapi/linux/virtio_9p.h
+F:	include/trace/events/9p.h
+
 
 A8293 MEDIA DRIVER
 M:	Antti Palosaari <crope@iki.fi>