wil6210: enlarge Tx status ring size

With multiple clients and in high throughput scenarios, Tx status ring
can get full and become a bottleneck in Tx transmission.
Set the default Tx status ring size order to 13, previous value was 12.
This will double the status ring size from 4K entries to 8K entries.

Signed-off-by: Ahmad Masri <amasri@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>