wil6210: tuning rings size

Tuning rings size for performance optimization.
Increasing Tx ring size, allows buffering more packets for HW, thus
eliminating idle periods which were observed with smaller ring at
high throughput, because HW was fetching packets faster than driver was
filling them into the TX ring. Rx ring was similarly increased to
avoid same problems in Rx.

Signed-off-by: Vladimir Shulman <qca_shulmanv@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>