drm/amdgpu/vcn: set no_user_fence for VCN v4.0 enc ring

drm/amdgpu/vcn: set no_user_fence 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.

Fixes: 8da1170a16e4 ("drm/amdgpu: add VCN4 ip block support")
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Yinjie Yao <yinjie.yao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit fd852c048b46f9825e904a4f3f4538fe9d8827d9)