[media] MAINTAINERS: Add entries for Aptina sensor drivers

Add an entry for the mt9m032, mt9p031, mt9t001 and mt9v032 Aptina sensor
drivers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>