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 14, previous value was 12.
This will double the status ring size from 4K entries to 16K entries.

Change-Id: Icbe2d85e4186ea5bc48ed9aa920341d923fcba4c
Signed-off-by: Ahmad Masri <amasri@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Git-commit: c903ece596cb80a51dc962925a88d2147b479c29
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


[merez@codeaurora.org: Fix commit text to match the size order and entries with the source change]
Signed-off-by: Maya Erez <merez@codeaurora.org>