tty: 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>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Timur Tabi <timur@tabi.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/of_serial.c

@@ -155,7 +155,7 @@ out:
 /*
  * Try to register a serial port
  */
-static struct of_device_id of_platform_serial_table[];
+static const struct of_device_id of_platform_serial_table[];
 static int of_platform_serial_probe(struct platform_device *ofdev)
 {
 	const struct of_device_id *match;
@@ -320,7 +320,7 @@ static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume);
 /*
  * A few common types, add more as needed.
  */
-static struct of_device_id of_platform_serial_table[] = {
+static const struct of_device_id of_platform_serial_table[] = {
 	{ .compatible = "ns8250",   .data = (void *)PORT_8250, },
 	{ .compatible = "ns16450",  .data = (void *)PORT_16450, },
 	{ .compatible = "ns16550a", .data = (void *)PORT_16550A, },