MAINTAINERS: update location of linux-doc tree

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

MAINTAINERS

@@ -3019,6 +3019,7 @@ F:	Documentation/
 X:	Documentation/ABI/
 X:	Documentation/devicetree/
 X:	Documentation/[a-z][a-z]_[A-Z][A-Z]/
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/jikos/doc.git
 
 DOUBLETALK DRIVER
 M:	"James R. Van Zandt" <jrv@vanzandt.mv.com>