MAINTAINERS: update input subsystem patterns

Add include/uapi/linux/input-event-codes.h and Documentation/input to
the file patterns, so that patches touching these files get copied
to linux-input mailing list.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

MAINTAINERS

@@ -6604,8 +6604,10 @@ S:	Maintained
 F:	drivers/input/
 F:	include/linux/input.h
 F:	include/uapi/linux/input.h
+F:	include/uapi/linux/input-event-codes.h
 F:	include/linux/input/
 F:	Documentation/devicetree/bindings/input/
+F:	Documentation/input/
 
 INPUT MULTITOUCH (MT) PROTOCOL
 M:	Henrik Rydberg <rydberg@bitmath.org>