ath9k: Add 'misc' file to debugfs, fix queue indexes.

Add a misc file to show hardware op-mode, irq setup,
number of various types of VIFs and more.

Also, previous patches were using the wrong xmit queue
indexes.  Change to use the internal ath9k indexes instead
of the mac80211 queue indexes.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>