drm: sti: Make of_device_id array const

Make of_device_id array const, because all OF functions handle it as const.
Signed-off-by: Kiran Padwal <kiran.padwal@smartplayin.com>

drivers/gpu/drm/sti/sti_hda.c

@@ -770,7 +770,7 @@ static int sti_hda_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct of_device_id hda_of_match[] = {
+static const struct of_device_id hda_of_match[] = {
 	{ .compatible = "st,stih416-hda", },
 	{ .compatible = "st,stih407-hda", },
 	{ /* end node */ }

drivers/gpu/drm/sti/sti_hdmi.c

@@ -677,7 +677,7 @@ static const struct component_ops sti_hdmi_ops = {
 	.unbind = sti_hdmi_unbind,
 };
 
-static struct of_device_id hdmi_of_match[] = {
+static const struct of_device_id hdmi_of_match[] = {
 	{
 		.compatible = "st,stih416-hdmi",
 		.data = &tx3g0c55phy_ops,

drivers/gpu/drm/sti/sti_tvout.c

@@ -624,7 +624,7 @@ static int sti_tvout_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct of_device_id tvout_of_match[] = {
+static const struct of_device_id tvout_of_match[] = {
 	{ .compatible = "st,stih416-tvout", },
 	{ .compatible = "st,stih407-tvout", },
 	{ /* end node */ }