drm/amdgpu: Add mqd support for the fence address

- Add a field in struct v11_gfx_mqd for userqueue
  fence address.

- Assign fence gpu VA address to the userqueue mqd
  fence address fields.

v2: Remove the mask and replace with lower_32_bits (Christian)

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>