mfd: sm501: Make of_device_id array const

Make of_device_id array const, because all OF functions
handle it as const.

Signed-off-by: Jingoo Han <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/sm501.c

···
 
 MODULE_ALIAS("platform:sm501");
 
-static struct of_device_id of_sm501_match_tbl[] = {
+static const struct of_device_id of_sm501_match_tbl[] = {
 	{ .compatible = "smi,sm501", },
 	{ /* end */ }
 };