drm/amdgpu/vcn: set no_user_fence for VCN v5.0.2 enc ring

drm/amdgpu/vcn: set no_user_fence for VCN v5.0.2 enc ring

VCN encoder and decoder rings do not support 64-bit user fence writes,
reject CS submissions with user fences.

Fixes: 8433398c789c ("drm/amdgpu: Add VCN v5_0_2")
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 48fc78c31ea7fec63100a772f863cf51b2f8cd0a)