qtnfmac: pass VIF info to SendChannel command

Do not assume whether wireless device can or can not handle switching
several interfaces on a single radio to different channels. Device will
handle it itself and will return appropriate error code.

Signed-off-by: Igor Mitsyanko <igor.mitsyanko.os@quantenna.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>