drm/omap: convert dss_mgr_enable to accept omap_channel

We are removing uses of 'struct omap_overlay_manager'. This patch
changes dss_mgr_enable() to accept 'enum omap_channel' instead of
'struct omap_overlay_manager'.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/dss/dsi.c

@@ -3876,7 +3876,7 @@ static int dsi_enable_video_output(struct omap_dss_device *dssdev, int channel)
 		dsi_if_enable(dsidev, true);
 	}
 
-	r = dss_mgr_enable(mgr);
+	r = dss_mgr_enable(mgr->id);
 	if (r)
 		goto err_mgr_enable;