drm: shmobile: fix warnings

drivers/gpu/drm/shmobile/shmob_drm_drv.c:300:5: warning: "CONFIG_PM_SLEEP" is not defined [-Wundef]

Always use #ifdef with CONFIG symbols, never just bare #if
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/shmobile/shmob_drm_drv.c

@@ -297,7 +297,7 @@ static struct drm_driver shmob_drm_driver = {
  * Power management
  */
 
-#if CONFIG_PM_SLEEP
+#ifdef CONFIG_PM_SLEEP
 static int shmob_drm_pm_suspend(struct device *dev)
 {
 	struct shmob_drm_device *sdev = dev_get_drvdata(dev);