radeonsi: Don't prefer interlaced for video decode

radeonsi: Don't prefer interlaced for video decode

Preferring interlaced results in all surfaces being allocated
as interlaced for H264 decode regardless of whether the decoded
pic is interlaced or progressive, which makes VA postproc
apply deinterlacing even for progressive pics.

Deinterlacing interlaced pics still works because VA frontend
will now reallocate surface as interlaced when decoding interlaced
pics.

Reviewed-by: Ruijing Dong <ruijing.dong@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24361>