tests/amdgpu/vcn: add Renoir VCN2.0 decode support

Renoir is the same family as Raven, but it's with VCN2.0,
so it has to use VCN2.0 reg set

Signed-off-by: Leo Liu <leo.liu@amd.com>
Reviewed-By: Thong Thai <thong.thai@amd.com>