drm/amdgpu/vcn3: replace ip based software ring decode with common vcn software ring decode

Replace ip based software ring decode with common vcn software ring decode.

Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Christian Koenig <Christian.Koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amdgpu: make software ring functions reuseable for newer VCN

Software ring will be supported only from VCN4

Signed-off-by: Leo Liu <leo.liu@amd.com>
Reviewed-by: James Zhu <James.Zhu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amdgpu: add VCN3.0 support for Sienna_Cichlid

With basic IP block functions and ring functions

Signed-off-by: Leo Liu <leo.liu@amd.com>
Reviewed-by: James Zhu <James.Zhu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>