Collect accumulated stats of tx attempts and successes
per rate and column for debugging purposes.
These stats can be read via debugfs file drv_tx_stats
and can also be reset by writing to this file.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>