mfd: rtsx: Fix build warnings for !PM

rtsx_pci_power_off() is called only from rtsx_pci_suspend(), which isn't
built when PM is disabled.

Signed-off-by: Thierry Reding <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/rtsx_pcr.c

···
 	mutex_unlock(&pcr->pcr_mutex);
 }
 
+#ifdef CONFIG_PM
 static void rtsx_pci_power_off(struct rtsx_pcr *pcr, u8 pm_state)
 {
 	if (pcr->ops->turn_off_led)
···
 	if (pcr->ops->force_power_down)
 		pcr->ops->force_power_down(pcr, pm_state);
 }
+#endif
 
 static int rtsx_pci_init_hw(struct rtsx_pcr *pcr)
 {