misc: apds990x: add CONFIG_PM_SLEEP to suspend/resume functions

Add CONFIG_PM_SLEEP to suspend/resume functions to fix the following
build warning when CONFIG_PM_SLEEP is not selected. This is because
sleep PM callbacks defined by SET_SYSTEM_SLEEP_PM_OPS are only used
when the CONFIG_PM_SLEEP is enabled.

drivers/misc/apds990x.c:1205:12: warning: 'apds990x_suspend' defined but not used [-Wunused-function]
drivers/misc/apds990x.c:1214:12: warning: 'apds990x_resume' defined but not used [-Wunused-function]

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/apds990x.c b/drivers/misc/apds990x.c
index 1efb6a4..98f9bb2 100644
--- a/drivers/misc/apds990x.c
+++ b/drivers/misc/apds990x.c
@@ -1201,7 +1201,7 @@
 	return 0;
 }
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 static int apds990x_suspend(struct device *dev)
 {
 	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
@@ -1224,10 +1224,6 @@
 
 	return 0;
 }
-#else
-#define apds990x_suspend  NULL
-#define apds990x_resume	  NULL
-#define apds990x_shutdown NULL
 #endif
 
 #ifdef CONFIG_PM_RUNTIME