drm/amdgpu: restore uvd fence seq in uvd resume

otherwise, uvd block will be never powered up in ring begin_use()
callback. uvd ring test will be fail in resume in rumtime pm.

Signed-off-by: Jim Qu <Jim.Qu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>