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>
diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
index d5d0626..9becba6 100644
--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -824,7 +824,7 @@
 };
 #endif
 
-static struct of_device_id serial_pxa_dt_ids[] = {
+static const struct of_device_id serial_pxa_dt_ids[] = {
 	{ .compatible = "mrvl,pxa-uart", },
 	{ .compatible = "mrvl,mmp-uart", },
 	{}