The channel_layout API was overhauled by FFmpeg [1-5]. The previous
bitmask channel_layout is replaced by a struct ch_layout which combines
the number of channels, a bitmask and other infos.
The resampler needs to be updated whenever using swresample > 4.5.100.
This commit makes the necessary changes.
[1] Bump minor versions after the channel layout changes
FFmpeg/FFmpeg@cdba98b
[2] lavc: switch to the new channel layout API
FFmpeg/FFmpeg@548aeb9
[3] avutil/channel_layout: Add a new channel layout API
FFmpeg/FFmpeg@086a804
[4] avframe: switch to the new channel layout API db6efa18
FFmpeg/FFmpeg@db6efa1
[5] swresample: convert to new channel layout API
FFmpeg/FFmpeg@8a5896e
Signed-off-by: pkv <pkv@obsproject.com>