Add libx265 encoder

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

libavcodec/allcodecs.c

@@ -441,6 +441,7 @@ void avcodec_register_all(void)
     REGISTER_ENCODER(LIBWAVPACK,        libwavpack);
     REGISTER_ENCODER(LIBWEBP,           libwebp);
     REGISTER_ENCODER(LIBX264,           libx264);
+    REGISTER_ENCODER(LIBX265,           libx265);
     REGISTER_ENCODER(LIBXAVS,           libxavs);
     REGISTER_ENCODER(LIBXVID,           libxvid);