[media] smiapp: Make suspend and resume functions __maybe_unused

The smiapp_suspend() and smiapp_resume() functions will end up being unused
if CONFIG_PM is enabled but CONFIG_PM_SLEEP is disabled, causing a
compiler warning from both of the function definitions. Fix this by
marking the functions with __maybe_unused.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/i2c/smiapp/smiapp-core.c

@@ -2741,7 +2741,7 @@ static const struct v4l2_subdev_internal_ops smiapp_internal_ops = {
  * I2C Driver
  */
 
-static int smiapp_suspend(struct device *dev)
+static int __maybe_unused smiapp_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
@@ -2766,7 +2766,7 @@ static int smiapp_suspend(struct device *dev)
 	return 0;
 }
 
-static int smiapp_resume(struct device *dev)
+static int __maybe_unused smiapp_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct v4l2_subdev *subdev = i2c_get_clientdata(client);