wil6210: multiple VIFs support for connections and data path

Track the connection status per-VIF.
The data path code is also updated to support multiple VIFs.
This includes RX and TX VRING management, NAPI poll loops,
RX reordering and related code.
Power management code used to check if the main interface
is up or based on connection state of the main interface,
adapt this code to take all VIFs into account.

Signed-off-by: Lior David <liord@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>