drm/amdgpu: change the default timeout for kernel compute queues

Change to 60s.  This matches what we already do in virtualization.
Infinite timeout can lead to deadlocks in the kernel.

Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>