MPSAFE.
- Preallocate a full set of QCBs during attach rather than allocating new
ones on demand to avoid allocations in the I/O path.
- Remove the explicit bus space tag/handle and use bus_*() on the
relevant 'struct resource' instead.
- Defer logical drive probing to an intrhook.
- Fix ida_detach() to detach and delete child devices (logical drives).
- Update the DMA handling to support EINPROGRESS by moving the work to
submit a mapped request into the bus_dma callback routine as well as
add support for freezing the queue when EINPROGRESS is encountered.
Tested by: Marco Steinbach coco executive-computing de