lavf/rawenc: Recognize more extensions to encode raw hevc.

Requested-by: Mike Brown, brown at mrvideo vidiot com

libavformat/rawenc.c

@@ -238,7 +238,7 @@ AVOutputFormat ff_h264_muxer = {
 AVOutputFormat ff_hevc_muxer = {
     .name              = "hevc",
     .long_name         = NULL_IF_CONFIG_SMALL("raw HEVC video"),
-    .extensions        = "hevc",
+    .extensions        = "hevc,h265,265",
     .audio_codec       = AV_CODEC_ID_NONE,
     .video_codec       = AV_CODEC_ID_HEVC,
     .write_header      = force_one_stream,