dmaengine: sun4i: support module autoloading

MODULE_DEVICE_TABLE() is missing, so the module isn't auto-loading on
supported systems. This commit adds the missing line so it loads
automatically when building it as a module and running on a system
with the early sunxi DMA engine.
Signed-off-by: Emilio López <emilio.lopez@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/sun4i-dma.c

@@ -1271,6 +1271,7 @@ static const struct of_device_id sun4i_dma_match[] = {
 	{ .compatible = "allwinner,sun4i-a10-dma" },
 	{ /* sentinel */ },
 };
+MODULE_DEVICE_TABLE(of, sun4i_dma_match);
 
 static struct platform_driver sun4i_dma_driver = {
 	.probe	= sun4i_dma_probe,