[][MAC80211][mt76][Fix connac2 testmode issues]

Fix the following testmode issues
1. Fix kernel crash issue when enabling unlimited TX in panther & merlin (adding aid > 0).
2. Fix mt76-test dump showing bug when freq_offset is set.
3. Fix kernel crash issue when tx_antenna_mask exceeds the limitation of chainmask.
   In this case, TX/RX frame should be blocked. However, the antenna sanity check logic will be bypassed
   when the user switches testmode state from off to tx_frames without first switching to idle manually.
4. Modify ZWDFS cmd format for syncing connac 2 & 3's format. Change the definition of offchan_ch from center
   to control chan and add offchan_center_ch.
5. Fix typos and code alignment.


Change-Id: Idd787cbe67e1406fd5c3b8a916cc2470cf29727a
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7598145
3 files changed