drm/armada: move the update of dplane->ctrl0 out of spinlock

It is not necessary to write dplane->ctrl0 under the CRTC spinlock, as
this is only accessed under process context where the DRM locks will
protect us instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/gpu/drm/armada/armada_overlay.c

@@ -275,9 +275,10 @@ static int armada_ovl_plane_disable(struct drm_plane *plane)
 
 	spin_lock_irq(&dcrtc->irq_lock);
 	armada_drm_vbl_event_remove(dcrtc, &dplane->vbl.update);
-	dplane->ctrl0 = 0;
 	spin_unlock_irq(&dcrtc->irq_lock);
 
+	dplane->ctrl0 = 0;
+
 	armada_drm_crtc_plane_disable(dcrtc, plane);
 
 	fb = xchg(&dplane->old_fb, NULL);