Now that we have graph and video-interfaces schemas, rework the media
related schemas to use them.

Cc: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>