greybus: camera: Remove support for legacy modules

Remove support for module implementing legacy version of camera bandwidth
requirements specifications, now that all available camera modules have
been updated to use the new version

Signed-off-by: Jacopo Mondi <jacopo.mondi@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>