drm/i915: Use intel_wm_plane_visible() on VLV/CHV as well

VLV/CHV don't have double buffered watermarks so they need to consider
the cursor visibility as a special case just like ILK-BDW. Let's use
the helper we have for that.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170303151928.23053-4-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_pm.c

@@ -1029,7 +1029,7 @@ static uint16_t vlv_compute_wm_level(const struct intel_crtc_state *crtc_state,
 	if (dev_priv->wm.pri_latency[level] == 0)
 		return USHRT_MAX;
 
-	if (!plane_state->base.visible)
+	if (!intel_wm_plane_visible(crtc_state, plane_state))
 		return 0;
 
 	cpp = plane_state->base.fb->format->cpp[0];
@@ -1203,7 +1203,7 @@ static bool vlv_plane_wm_compute(struct intel_crtc_state *crtc_state,
 	int level;
 	bool dirty = false;
 
-	if (!plane_state->base.visible) {
+	if (!intel_wm_plane_visible(crtc_state, plane_state)) {
 		dirty |= vlv_raw_plane_wm_set(crtc_state, 0, plane_id, 0);
 		goto out;
 	}