regulator: max1586: Fix W=1 build warning when CONFIG_OF=n

Fix below warning when CONFIG_OF=n:

drivers/regulator/max1586.c:204:34: warning: ‘max1586_of_match’ defined but not used [-Wunused-const-variable=]
  204 | static const struct of_device_id max1586_of_match[] = {
      |                                  ^~~~~~~~~~~~~~~~
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200821111601.26243417@xhacker.debianSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/max1586.c

@@ -201,7 +201,7 @@ static int of_get_max1586_platform_data(struct device *dev,
 	return 0;
 }
 
-static const struct of_device_id max1586_of_match[] = {
+static const struct of_device_id __maybe_unused max1586_of_match[] = {
 	{ .compatible = "maxim,max1586", },
 	{},
 };