drm/exynos: Suspend/resume is unused if !PM

Protect the suspend and resume callbacks with an #ifdef CONFIG_PM_SLEEP
guard to avoid "defined but not used" warnings.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -304,6 +304,7 @@ int exynos_atomic_commit(struct drm_device *dev, struct drm_atomic_state *state,
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
 static int exynos_drm_suspend(struct drm_device *dev, pm_message_t state)
 {
 	struct drm_connector *connector;
@@ -340,6 +341,7 @@ static int exynos_drm_resume(struct drm_device *dev)
 
 	return 0;
 }
+#endif
 
 static int exynos_drm_open(struct drm_device *dev, struct drm_file *file)
 {