cpufreq: qcom-hw: Use optional irq API

Use platform_get_irq_optional() to avoid a noisy error message when the
irq isn't specified. The irq is definitely optional given that we only
care about errors that are -EPROBE_DEFER here.

Cc: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/qcom-cpufreq-hw.c

@@ -374,9 +374,11 @@ static int qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy, int index)
 	 * Look for LMh interrupt. If no interrupt line is specified /
 	 * if there is an error, allow cpufreq to be enabled as usual.
 	 */
-	data->throttle_irq = platform_get_irq(pdev, index);
-	if (data->throttle_irq <= 0)
-		return data->throttle_irq == -EPROBE_DEFER ? -EPROBE_DEFER : 0;
+	data->throttle_irq = platform_get_irq_optional(pdev, index);
+	if (data->throttle_irq == -ENXIO)
+		return 0;
+	if (data->throttle_irq < 0)
+		return data->throttle_irq;
 
 	data->cancel_throttle = false;
 	data->policy = policy;