[media] vsp1: use __maybe_unused for PM handlers

Building without CONFIG_PM results in a harmless warning from
slightly incorrect #ifdef guards:

drivers/media/platform/vsp1/vsp1_drv.c:525:12: error: 'vsp1_pm_runtime_resume' defined but not used [-Werror=unused-function]
drivers/media/platform/vsp1/vsp1_drv.c:516:12: error: 'vsp1_pm_runtime_suspend' defined but not used [-Werror=unused-function]

This removes the existing #ifdef and instead marks all four
PM functions as __maybe_unused.

Fixes: 1e6af546 ("[media] v4l: vsp1: Implement runtime PM support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/vsp1/vsp1_drv.c

@@ -504,8 +504,7 @@ void vsp1_device_put(struct vsp1_device *vsp1)
  * Power Management
  */
 
-#ifdef CONFIG_PM_SLEEP
-static int vsp1_pm_suspend(struct device *dev)
+static int __maybe_unused vsp1_pm_suspend(struct device *dev)
 {
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 
@@ -515,7 +514,7 @@ static int vsp1_pm_suspend(struct device *dev)
 	return 0;
 }
 
-static int vsp1_pm_resume(struct device *dev)
+static int __maybe_unused vsp1_pm_resume(struct device *dev)
 {
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 
@@ -524,9 +523,8 @@ static int vsp1_pm_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
-static int vsp1_pm_runtime_suspend(struct device *dev)
+static int __maybe_unused vsp1_pm_runtime_suspend(struct device *dev)
 {
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 
@@ -535,7 +533,7 @@ static int vsp1_pm_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int vsp1_pm_runtime_resume(struct device *dev)
+static int __maybe_unused vsp1_pm_runtime_resume(struct device *dev)
 {
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 	int ret;