ath10k: mark PM functions as __maybe_unused

When CONFIG_PM_SLEEP is disabled, we get a compile-time
warning:

drivers/net/wireless/ath/ath10k/pci.c:3417:12: error: 'ath10k_pci_pm_resume' defined but not used [-Werror=unused-function]
 static int ath10k_pci_pm_resume(struct device *dev)
            ^~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/ath/ath10k/pci.c:3401:12: error: 'ath10k_pci_pm_suspend' defined but not used [-Werror=unused-function]
 static int ath10k_pci_pm_suspend(struct device *dev)

Rather than fixing the #ifdef, this just marks both functions
as __maybe_unused, which is a more robust way to do this.

Fixes: 32faa3f0ee50 ("ath10k: add the PCI PM core suspend/resume ops")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/pci.c

@@ -3396,9 +3396,7 @@ static void ath10k_pci_remove(struct pci_dev *pdev)
 
 MODULE_DEVICE_TABLE(pci, ath10k_pci_id_table);
 
-#ifdef CONFIG_PM
-
-static int ath10k_pci_pm_suspend(struct device *dev)
+static __maybe_unused int ath10k_pci_pm_suspend(struct device *dev)
 {
 	struct ath10k *ar = dev_get_drvdata(dev);
 	int ret;
@@ -3414,7 +3412,7 @@ static int ath10k_pci_pm_suspend(struct device *dev)
 	return ret;
 }
 
-static int ath10k_pci_pm_resume(struct device *dev)
+static __maybe_unused int ath10k_pci_pm_resume(struct device *dev)
 {
 	struct ath10k *ar = dev_get_drvdata(dev);
 	int ret;
@@ -3433,7 +3431,6 @@ static int ath10k_pci_pm_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(ath10k_pci_pm_ops,
 			 ath10k_pci_pm_suspend,
 			 ath10k_pci_pm_resume);
-#endif
 
 static struct pci_driver ath10k_pci_driver = {
 	.name = "ath10k_pci",