CVE-2026-63853 drm/amdgpu/vcn: set no_user_fence for VCN v4.0 enc ring

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: set nouserfence for VCN v4.0 enc ring VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences. cherry picked from commit fd852c048b46f9825e904a4f3f4538fe9d8827...