qtnfmac: pass complete channel data between driver and firmware

Center frequency is not enough to describe the channel in HT and VHT
modes. For 40MHz and 80MHz channels both primary channel and center
frequency should be specified in order to qualify channel completely.
This change adds primary channel info into qlink_chandef structure.

Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>