drm/sun4i: Use embedded tcon pointer to get the tcon's output port node

A pointer to the underlying tcon of the crtc was added to the sun4i_crtc
structure in "drm/sun4i: Add backend and tcon pointers to sun4i_crtc".
However the crtc init function was still using the copy from sun4i_drv
to set drm_crtc.port. This was an oversight when the patches were
reordered.

Switch to using the embedded tcon pointer to get the tcon's ouptut port
and assign it to drm_crtc.port.

This makes it possible to remove the usage of sun4i_drv completely in
subsequent patches.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/gpu/drm/sun4i/sun4i_crtc.c

@@ -183,7 +183,7 @@ struct sun4i_crtc *sun4i_crtc_init(struct drm_device *drm)
 	drm_crtc_helper_add(&scrtc->crtc, &sun4i_crtc_helper_funcs);
 
 	/* Set crtc.port to output port node of the tcon */
-	scrtc->crtc.port = of_graph_get_port_by_id(drv->tcon->dev->of_node,
+	scrtc->crtc.port = of_graph_get_port_by_id(scrtc->tcon->dev->of_node,
 						   1);
 
 	/* Set possible_crtcs to this crtc for overlay planes */