mmc: sdhci-acpi: Remove redundant runtime PM idle callback

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-acpi.c

@@ -448,18 +448,13 @@ static int sdhci_acpi_runtime_resume(struct device *dev)
 	return sdhci_runtime_resume_host(c->host);
 }
 
-static int sdhci_acpi_runtime_idle(struct device *dev)
-{
-	return 0;
-}
-
 #endif
 
 static const struct dev_pm_ops sdhci_acpi_pm_ops = {
 	.suspend		= sdhci_acpi_suspend,
 	.resume			= sdhci_acpi_resume,
 	SET_RUNTIME_PM_OPS(sdhci_acpi_runtime_suspend,
-			sdhci_acpi_runtime_resume, sdhci_acpi_runtime_idle)
+			sdhci_acpi_runtime_resume, NULL)
 };
 
 static struct platform_driver sdhci_acpi_driver = {