wil6210: prevent access to vring_tx_data lock during its init

wil_tx_vring locks the vring_tx_data lock before accessing the TX
vring to check if it is enabled and valid for use.
In case of quick disconnect / connect events for the same station,
spin_lock(&txdata->lock) can be called during the lock initialization
in the vring init function.
To prevent such a race, the TX vrings spin lock should be initialized
once during wil6210 driver initialization.

Change-Id: I11fa67f7040c4a728f0cd7633f4fbb829ac165d0
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
git-commit: 875e9439
Git-repo: https://github.com/kvalo/ath.git


CRs-Fixed: 982882
Signed-off-by: Maya Erez <merez@codeaurora.org>