avfilter/trim: support all channel numbers in atrim filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavfilter/trim.c

@@ -381,6 +381,7 @@ AVFilter ff_af_atrim = {
     .name        = "atrim",
     .description = NULL_IF_CONFIG_SMALL("Pick one continuous section from the input, drop the rest."),
     .init        = init,
+    .query_formats = ff_query_formats_all,
     .priv_size   = sizeof(TrimContext),
     .priv_class  = &atrim_class,
     .inputs      = atrim_inputs,