AMDGPU: Invert handling of enqueued block detection

Invert the sense of the attribute and let the attributor figure this
out like everything else. If needed we can have the not-OpenCL
languages set amdgpu-no-default-queue and amdgpu-no-completion-action
up front so they never have to pay the cost.

There are also so many of these now, the offset use API should
probably consider all of them at once. Maybe they should merge into
one attribute with used fields. Having separate functions for each
field in AMDGPUBaseInfo is also not the greatest API (might as well
fix this when the patch to get the object version from the module
lands).