serial: 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 8aff0b4..91e36bc 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -239,7 +239,7 @@
 	},
 };
 
-static struct platform_device_id imx_uart_devtype[] = {
+static const struct platform_device_id imx_uart_devtype[] = {
 	{
 		.name = "imx1-uart",
 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],