ath9k: Check for pending frames properly

ath9k: Check for pending frames properly

Pending frames in the driver can be present
either in the HW queues or SW. ath9k_has_pending_frames()
currently checks for the HW queues first and then
checks if any ACs are queued in the driver.

In MCC mode, we need to check the HW queues alone, since
the SW queues are just marked as 'stopped' - they will
be processed in the next context switch. But since we
don't differentiate this now, mention whether we want
to check if there are frames in the SW queues.

* The flush() callback checks both HW and SW queues.
* The tx_frames_pending() callback does the same.
* The call to __ath9k_flush() in MCC mode checks HW queues alone.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>