regulator: fan53555: Fix W=1 build warning when CONFIG_OF=n

Fix below warning when CONFIG_OF=n:

drivers/regulator/fan53555.c:439:34: warning: ‘fan53555_dt_ids’ defined but not used [-Wunused-const-variable=]
  439 | static const struct of_device_id fan53555_dt_ids[] = {
      |                                  ^~~~~~~~~~~~~~~
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200821111324.430fe1da@xhacker.debianSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/fan53555.c

@@ -436,7 +436,7 @@ static struct fan53555_platform_data *fan53555_parse_dt(struct device *dev,
 	return pdata;
 }
 
-static const struct of_device_id fan53555_dt_ids[] = {
+static const struct of_device_id __maybe_unused fan53555_dt_ids[] = {
 	{
 		.compatible = "fcs,fan53526",
 		.data = (void *)FAN53526_VENDOR_FAIRCHILD,