drm: xlnx: zynqmp: Fix max dma segment size

Fix "mapping sg segment longer than device claims to support" warning by
setting the max segment size.

Fixes: d76271d22694 ("drm: xlnx: DRM/KMS driver for Xilinx ZynqMP DisplayPort Subsystem")
Reviewed-by: Sean Anderson <[e-mail]>
Tested-by: Sean Anderson <[e-mail]>
Signed-off-by: Tomi Valkeinen <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/xlnx/zynqmp_dpsub.c

···
 	if (ret)
 		return ret;
 
+	dma_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));
+
 	/* Try the reserved memory. Proceed if there's none. */
 	of_reserved_mem_device_init(&pdev->dev);