Input: twl6040-vibra - fix compiler warning

Fix warning from Geert's build summary emails by changing "if" to
"ifdef". Thsi should fix the following:

drivers/input/misc/twl6040-vibra.c:231:5: warning: "CONFIG_PM_SLEEP" is not defined

Builds cleanly with CONFIG_PM_SLEEP enabled or disabled.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/misc/twl6040-vibra.c

@@ -228,7 +228,7 @@ static void twl6040_vibra_close(struct input_dev *input)
 	mutex_unlock(&info->mutex);
 }
 
-#if CONFIG_PM_SLEEP
+#ifdef CONFIG_PM_SLEEP
 static int twl6040_vibra_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);