dmaengine: imx: Constify platform_device_id

The platform_device_id is not modified by the driver and core uses it as
const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 62bbd79..77b6aab 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -420,7 +420,7 @@
 	.script_addrs = &sdma_script_imx6q,
 };
 
-static struct platform_device_id sdma_devtypes[] = {
+static const struct platform_device_id sdma_devtypes[] = {
 	{
 		.name = "imx25-sdma",
 		.driver_data = (unsigned long)&sdma_imx25,