Revert "radeonsi/vcn: AV1 skip the redundant bs resize"

Currently ffmpeg has a bug in VAAPI AV1 decode that in some cases
it submits the same slice data buffer as many times as there is tiles.
However, in other cases it behaves correctly and all slice data buffers
contain different parts of bitstream to decode which this change breaks.

Now that the va frontend is passing correct offsets, this fixes decoding
AV1-TEST-VECTORS/av1-1-b8-22-svc-L1T2 with ffmpeg.

This reverts commit e6701f7231.

Cc: mesa-stable
Reviewed-by: Leo Liu <leo.liu@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28960>

src/gallium/drivers/radeonsi/radeon_vcn_dec.c

@@ -2882,9 +2882,6 @@ static void radeon_dec_decode_bitstream(struct pipe_video_codec *decoder,
    if (!dec->bs_ptr)
       return;
 
-   if (dec->bs_size && dec->stream_type == RDECODE_CODEC_AV1)
-      return;
-
    unsigned long total_bs_size = dec->bs_size;
    for (i = 0; i < num_buffers; ++i)
       total_bs_size += sizes[i];