[][MAC80211][mt76][Add vendor command attribute for RTS BW signaling for mt76.]

[Description]
Add vendor command attribute for RTS BW signaling for mt76.
Ref: WFA 11AC test case 4.2.59A

[Release-log]

Change-Id: Ide1547d2b00b3b4502259904d1f565bd085b2acb
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7069418
1 file changed