ahci: st: Make of_device_id array const

Make of_device_id array const, because all OF functions handle it as const.
Signed-off-by: NKiran Padwal <kiran.padwal21@gmail.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NTejun Heo <tj@kernel.org>

drivers/ata/ahci_st.c

@@ -221,7 +221,7 @@ static int st_ahci_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(st_ahci_pm_ops, st_ahci_suspend, st_ahci_resume);
 
-static struct of_device_id st_ahci_match[] = {
+static const struct of_device_id st_ahci_match[] = {
 	{ .compatible = "st,ahci", },
 	{},
 };