drm/amdgpu: cleanup fence queue init v2

Move the fence related stuff into amdgpu_fence.c

v2: rework commit message, cause this is actually not a bug

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming <Zhou&lt;david1.zhou@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>