i2c: st: use pm_sleep_ptr to avoid ifdef CONFIG_PM_SLEEP

Rely on pm_sleep_ptr when setting the pm ops and get rid
of the ifdef CONFIG_PM_SLEEP around suspend/resume functions.
Signed-off-by: Alain Volmat <avolmat@me.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-st.c

@@ -740,7 +740,6 @@ static int st_i2c_xfer(struct i2c_adapter *i2c_adap,
 	return (ret < 0) ? ret : i;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int st_i2c_suspend(struct device *dev)
 {
 	struct st_i2c_dev *i2c_dev = dev_get_drvdata(dev);
@@ -762,11 +761,7 @@ static int st_i2c_resume(struct device *dev)
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(st_i2c_pm, st_i2c_suspend, st_i2c_resume);
-#define ST_I2C_PM	(&st_i2c_pm)
-#else
-#define ST_I2C_PM	NULL
-#endif
+static DEFINE_SIMPLE_DEV_PM_OPS(st_i2c_pm, st_i2c_suspend, st_i2c_resume);
 
 static u32 st_i2c_func(struct i2c_adapter *adap)
 {
@@ -901,7 +896,7 @@ static struct platform_driver st_i2c_driver = {
 	.driver = {
 		.name = "st-i2c",
 		.of_match_table = st_i2c_match,
-		.pm = ST_I2C_PM,
+		.pm = pm_sleep_ptr(&st_i2c_pm),
 	},
 	.probe = st_i2c_probe,
 	.remove = st_i2c_remove,