iwlwifi: pcie: introduce a000 TX queues management

In a000 devices the TX handling is different in a few ways:
* Queues are allocated dynamically
* DQA is enabled by default
* Driver shouldn't access TFH registers - ucode configures it
  all in SCD_QUEUE_CFG command

Support all this in a new API with op mode, where op mode sends
the command, transport will allocate the queue dynamically, fill
in DMA properties, send the command to FW and get the ID back.
Current implementation only sets the new transport API and fills
the DMA properties.
Future patches will complete the other parts.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>