drm/amdgpu: use queue 0 for kiq ring

It must use queue id 0, because CGPG_IDLE/SAVE/LOAD/RUN only can be issued on
queue 0.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>