drivers/video: fsl-diu-fb: simplify platforms that have only one port

Allow the platform code not to define a value for diu_ops.set_monitor_port.
This would be for platforms that only have one monitor port.
set_monitor_port() will never be called with an unsupported port anyway.

Signed-off-by: Timur Tabi <timur@freescale.com>
1 file changed