drm: omapdrm: acx565akm: Remove unneeded check for OF node

As non-DT booting is no longer supported, the only way to instantiate
the device is through an OF node, which is guaranteed to be present.
Remove the unneeded check.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/displays/panel-sony-acx565akm.c

@@ -720,6 +720,9 @@ static int acx565akm_probe(struct spi_device *spi)
 
 	dev_dbg(&spi->dev, "%s\n", __func__);
 
+	if (!spi->dev.of_node)
+		return -ENODEV;
+
 	spi->mode = SPI_MODE_3;
 
 	ddata = devm_kzalloc(&spi->dev, sizeof(*ddata), GFP_KERNEL);