lavfi: port libmpcodecs delogo filter

The ported filter supports named option parsing and more YUV formats.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavfilter/allfilters.c

@@ -45,6 +45,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER (COPY,        copy,        vf);
     REGISTER_FILTER (CROP,        crop,        vf);
     REGISTER_FILTER (CROPDETECT,  cropdetect,  vf);
+    REGISTER_FILTER (DELOGO,      delogo,      vf);
     REGISTER_FILTER (DRAWBOX,     drawbox,     vf);
     REGISTER_FILTER (DRAWTEXT,    drawtext,    vf);
     REGISTER_FILTER (FADE,        fade,        vf);