cpufreq: cpufreq-cpu0: Use devm_regulator_get_optional()

Since the cpufreq-cpu0 driver is capable of coping without a software
controllable regulator and would be confused by a dummy one it should
use devm_regulator_get_optional() to ensure no dummy is provided.
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/cpufreq/cpufreq-cpu0.c

@@ -197,7 +197,7 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 	cpu_dev = &pdev->dev;
 	cpu_dev->of_node = np;
 
-	cpu_reg = devm_regulator_get(cpu_dev, "cpu0");
+	cpu_reg = devm_regulator_get_optional(cpu_dev, "cpu0");
 	if (IS_ERR(cpu_reg)) {
 		/*
 		 * If cpu0 regulator supply node is present, but regulator is