mfd: Add missing #ifdef around tc3589x PM block

The CONFIG_PM code was unconditionally compiled in despite
the dev_pm_ops only being included into the driver struct
if used. Fix this by adding the missing #ifdef.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/tc3589x.c b/drivers/mfd/tc3589x.c
index c27e515..de97974 100644
--- a/drivers/mfd/tc3589x.c
+++ b/drivers/mfd/tc3589x.c
@@ -357,6 +357,7 @@
 	return 0;
 }
 
+#ifdef CONFIG_PM
 static int tc3589x_suspend(struct device *dev)
 {
 	struct tc3589x *tc3589x = dev_get_drvdata(dev);
@@ -387,6 +388,7 @@
 
 static const SIMPLE_DEV_PM_OPS(tc3589x_dev_pm_ops, tc3589x_suspend,
 						tc3589x_resume);
+#endif
 
 static const struct i2c_device_id tc3589x_id[] = {
 	{ "tc3589x", 24 },