drm/amdgpu: add a workaround for GDS ordered append hangs with compute queues

I'm not increasing the DRM version because GDS isn't totally without bugs yet.

v2: update emit_ib_size

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>