wil6210: fix timing of netif_carrier_on indication

netif_carrier_on indication was too late. In case Rx packet received
before netif_carrier_on indication, upper layers could not send
Tx packet back.

The fix is to indicate netif_carrier_on earlier:
for STA, indicate netif_carrier_on when association starts.
for AP/PCP, indicate netif_carrier_on upon starting AP/PCP.

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