drm/imx: imx-tve: remove unneeded 'or' operation

There is no need for doing an extra 'or' operation when reading
the return value from of_property_read_u32().

Just do a simple read instead.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>