mfd: sec-core: Make of_device_id array const

Array of struct of_device_id may be be const as expected by both
of_match_table field and of_match_node() call.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/sec-core.c

@@ -90,7 +90,7 @@ static const struct mfd_cell s2mpa01_devs[] = {
 };
 
 #ifdef CONFIG_OF
-static struct of_device_id sec_dt_match[] = {
+static const struct of_device_id sec_dt_match[] = {
 	{	.compatible = "samsung,s5m8767-pmic",
 		.data = (void *)S5M8767X,
 	}, {