drm/amdgpu: fix no ACK from LDS read during stress test for Arcturus

Set mmSQ_CONFIG.DISABLE_SMEM_SOFT_CLAUSE as W/R.

Signed-off-by: Le Ma <le.ma@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>