gstplaysink: don't set async of custom text-sink to false

set async to false lead to A/V sync problem when seeking.
the preroll need use GAP event instead of set async to false.

Upstream Status: Inappropriate [i.MX specific]

Signed-off-by: Mingke Wang <mingke.wang@freescale.com>
diff --git a/gst/playback/gstplaysink.c b/gst/playback/gstplaysink.c
old mode 100644
new mode 100755
index 89cd225..1832b63
--- a/gst/playback/gstplaysink.c
+++ b/gst/playback/gstplaysink.c
@@ -2456,7 +2456,7 @@
           G_TYPE_BOOLEAN);
       if (elem) {
         /* make sure the sparse subtitles don't participate in the preroll */
-        g_object_set (elem, "async", FALSE, NULL);
+        //g_object_set (elem, "async", FALSE, NULL);
         GST_DEBUG_OBJECT (playsink, "adding custom text sink");
         gst_bin_add (bin, chain->sink);
         /* NOTE streamsynchronizer needs streams decoupled */