drm/amdgpu: add vcn decode ring type and functions

Add the ring function callbacks for the decode ring.

Signed-off-by: Leo Liu <leo.liu@amd.com>
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2 files changed