regulator: vexpress: 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]>
Acked-by: Pawel Moll <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/vexpress.c

···
 	return 0;
 }
 
-static struct of_device_id vexpress_regulator_of_match[] = {
+static const struct of_device_id vexpress_regulator_of_match[] = {
 	{ .compatible = "arm,vexpress-volt", },
 	{ }
 };