regulator: qcom-rpmh: Fix W=1 build warning when CONFIG_OF=n

Fix below warning when CONFIG_OF=n:

drivers/regulator/qcom-rpmh-regulator.c:970:34: warning: ‘rpmh_regulator_match_table’ defined but not used [-Wunused-const-variable=]
  970 | static const struct of_device_id rpmh_regulator_match_table[] = {
      |                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20200821111913.1096f7cc@xhacker.debianSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/qcom-rpmh-regulator.c

@@ -967,7 +967,7 @@ static int rpmh_regulator_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id rpmh_regulator_match_table[] = {
+static const struct of_device_id __maybe_unused rpmh_regulator_match_table[] = {
 	{
 		.compatible = "qcom,pm8005-rpmh-regulators",
 		.data = pm8005_vreg_data,