rtc: make of_device_ids const

of_device_ids (i.e. compatible strings and the respective data) are not
supposed to change at runtime. All functions working with of_device_ids
provided by <linux/of.h> work with const of_device_ids. This allows to
mark all struct of_device_id below drivers/rtc const, too.

Signed-off-by: Uwe Kleine-König <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/rtc/rtc-isl12022.c

···
 }
 
 #ifdef CONFIG_OF
-static struct of_device_id isl12022_dt_match[] = {
+static const struct of_device_id isl12022_dt_match[] = {
 	{ .compatible = "isl,isl12022" },
 	{ },
 };

drivers/rtc/rtc-mpc5121.c

···
 }
 
 #ifdef CONFIG_OF
-static struct of_device_id mpc5121_rtc_match[] = {
+static const struct of_device_id mpc5121_rtc_match[] = {
 	{ .compatible = "fsl,mpc5121-rtc", },
 	{ .compatible = "fsl,mpc5200-rtc", },
 	{},