[media] Kconfig: Split the core support options from the driver ones

Better arrange the remote controller driver items to happen after the
core support, on their proper menus, and making clerarer what is media
core options and what is media driver options.

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