greybus: camera: Hardcode the APB-A CSI-2 TX parameters

Camera modules will stop reporting the number of lines per second,
hardcode the parameter in the driver until the APB-A CSI-2 TX
configuration protocol gets updated as well to use a more appropriate
form of bandwidth information.

The number of data lanes is also hardcoded as it should not depend on
the module's CSI-2 bus configuration.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>