regulator: tps65023: Fix W=1 build warning when CONFIG_OF=n

Fix below warning when CONFIG_OF=n:

drivers/regulator/tps65023-regulator.c:319:34: warning: ‘tps65023_of_match’ defined but not used [-Wunused-const-variable=]
  319 | static const struct of_device_id tps65023_of_match[] = {
      |                                  ^~~~~~~~~~~~~~~~~
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200821112009.58ee8511@xhacker.debianSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/tps65023-regulator.c

@@ -316,7 +316,7 @@ static int tps_65023_probe(struct i2c_client *client,
 	return 0;
 }
 
-static const struct of_device_id tps65023_of_match[] = {
+static const struct of_device_id __maybe_unused tps65023_of_match[] = {
 	{ .compatible = "ti,tps65020", .data = &tps65020_drv_data},
 	{ .compatible = "ti,tps65021", .data = &tps65021_drv_data},
 	{ .compatible = "ti,tps65023", .data = &tps65023_drv_data},