avformat/mpegtsenc: add AVSV format_identifier for AVS standard

Listing of Registered Identifiers:
https://smpte-ra.org/registered-mpeg-ts-ids

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>

libavformat/mpegtsenc.c

@@ -789,6 +789,9 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
                 put_registration_descriptor(&q, MKTAG('V', 'C', '-', '1'));
             } else if (stream_type == STREAM_TYPE_VIDEO_HEVC && s->strict_std_compliance <= FF_COMPLIANCE_NORMAL) {
                 put_registration_descriptor(&q, MKTAG('H', 'E', 'V', 'C'));
+            } else if (stream_type == STREAM_TYPE_VIDEO_CAVS || stream_type == STREAM_TYPE_VIDEO_AVS2 ||
+                       stream_type == STREAM_TYPE_VIDEO_AVS3) {
+                put_registration_descriptor(&q, MKTAG('A', 'V', 'S', 'V'));
             }
             break;
         case AVMEDIA_TYPE_DATA: