dmaengine: constify of_device_id array

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c
index 6f7f435..3ac9256 100644
--- a/drivers/dma/k3dma.c
+++ b/drivers/dma/k3dma.c
@@ -654,7 +654,7 @@
 	kfree(ds);
 }
 
-static struct of_device_id k3_pdma_dt_ids[] = {
+static const struct of_device_id k3_pdma_dt_ids[] = {
 	{ .compatible = "hisilicon,k3-dma-1.0", },
 	{}
 };