iio: gyro: bmg160: only set power state if PM_RUNTIME is defined

When CONFIG_PM_RUNTIME is not defined and bmg160 tries to power
off the device, bmg160_set_power_state will call pm_runtime_put_autosuspend,
which is not implemented (wil return -ENOSYS).

Only call bmg160_set_power_state when CONFIG_PM_RUNTIME is defined.
Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/gyro/bmg160.c

@@ -237,6 +237,7 @@ static int bmg160_chip_init(struct bmg160_data *data)
 
 static int bmg160_set_power_state(struct bmg160_data *data, bool on)
 {
+#ifdef CONFIG_PM_RUNTIME
 	int ret;
 
 	if (on)
@@ -251,6 +252,7 @@ static int bmg160_set_power_state(struct bmg160_data *data, bool on)
 			"Failed: bmg160_set_power_state for %d\n", on);
 		return ret;
 	}
+#endif
 
 	return 0;
 }