drm/armada: move event sending into armada_plane_work

Move the sending of events into the armada_plane_work structure, and
combine the processing in armada_drm_plane_work_call().

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

drivers/gpu/drm/armada/armada_crtc.h

@@ -40,6 +40,7 @@ struct armada_plane_work {
 	void (*cancel)(struct armada_crtc *, struct armada_plane_work *);
 	struct drm_plane *plane;
 	struct drm_framebuffer *old_fb;
+	struct drm_pending_vblank_event *event;
 };
 
 struct armada_plane_state {