media: dt-bindings: media: Add macros for video interface bus types

Add a new dt-bindings/media/video-interfaces.h header that defines
macros corresponding to the bus types from media/video-interfaces.yaml.
This allows avoiding hardcoded constants in device tree sources.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>