[][openwrt-patches-21.02: remove mt76 zw-dfs]

[Description]
Remove zero-wait dfs related patches of mac80211 and mt76, since they're
already merged in openwrt and mt76 master.

[Release-log]
N/A

Change-Id: Ib1fceb9c5cdbcaf315ee0be51c6b625db2c91818
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5583121
2 files changed