media: dt-bindings: Use new video interface bus type macros in examples

Now that a header exists with macros for the media interface bus-type
values, replace hardcoding numerical constants with the corresponding
macros in the DT binding examples.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>