amltsdmx: CF1 fix build warning on yocto 3.0 [1/1]

PD#SWPL-180069

Problem:
GST_MTS_DESC_EXT_DVB_AC4 exsit since gst 1.18

Solution:
fix build warning on yocto 3.0

Verify:
ap222

Change-Id: I7926ae5d33ea85ae0ee7c21b798eba780ec7b199
Signed-off-by: bo.xiao <bo.xiao@amlogic.com>
diff --git a/aml-tsdemux/amltsdemux.c b/aml-tsdemux/amltsdemux.c
index b952003..c233f79 100644
--- a/aml-tsdemux/amltsdemux.c
+++ b/aml-tsdemux/amltsdemux.c
@@ -1469,6 +1469,7 @@
         break;
       }
 
+#if ((GST_VERSION_MAJOR == 1) && (GST_VERSION_MINOR >= 18))
       desc = amlts_get_descriptor_from_stream_with_extension (bstream,
           GST_MTS_DESC_DVB_EXTENSION, GST_MTS_DESC_EXT_DVB_AC4);
       if (desc) {
@@ -1477,6 +1478,7 @@
         caps = gst_caps_new_empty_simple ("audio/x-ac4");
         break;
       }
+#endif
 
       desc = amlts_get_descriptor_from_stream (bstream, GST_MTS_DESC_DVB_AC3);
       if (desc) {