radeonsi/vcn: Add UDT support for VCN5

UDT uses decode target buffers directly as references.

Reviewed-by: Leo Liu <leo.liu@amd.com>
Reviewed-by: Ruijing Dong <ruijing.dong@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33641>
3 files changed