drm: Fix up drm_atomic_state_helper.[hc] extraction

I've misplaced two functions by accident:
- drm_atomic_helper_duplicate_state is really part of the
  resume/suspend/shutdown device-wide helpers.
- drm_atomic_helper_legacy_gamma_set is part of the legacy ioctl
  compat helpers.

Move them both back.

Fixes: 9ef8a9dc4b21 ("drm: Extract drm_atomic_state_helper.[hc]")
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181128100728.4674-1-daniel.vetter@ffwll.ch
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 25ca009..58214be 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -127,6 +127,9 @@ int __drm_atomic_helper_set_config(struct drm_mode_set *set,
 int drm_atomic_helper_disable_all(struct drm_device *dev,
 				  struct drm_modeset_acquire_ctx *ctx);
 void drm_atomic_helper_shutdown(struct drm_device *dev);
+struct drm_atomic_state *
+drm_atomic_helper_duplicate_state(struct drm_device *dev,
+				  struct drm_modeset_acquire_ctx *ctx);
 struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev);
 int drm_atomic_helper_commit_duplicated_state(struct drm_atomic_state *state,
 					      struct drm_modeset_acquire_ctx *ctx);
@@ -145,6 +148,10 @@ int drm_atomic_helper_page_flip_target(
 				uint32_t flags,
 				uint32_t target,
 				struct drm_modeset_acquire_ctx *ctx);
+int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
+				       u16 *red, u16 *green, u16 *blue,
+				       uint32_t size,
+				       struct drm_modeset_acquire_ctx *ctx);
 
 /**
  * drm_atomic_crtc_for_each_plane - iterate over planes currently attached to CRTC