drm/amdgpu: update VCN codec support for Yellow Carp

Supports AV1.  Mesa already has support for this and
doesn't rely on the kernel caps for yellow carp, so
this was already working from an application perspective.

Fixes: 55439817 ("amdgpu/nv.c - Added video codec support for Yellow Carp")
Bug: drm/amd#2002


Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org