[][mac80211][mt76][remove unused patchs which have upstream done]

[Description]
Remove patches based on mt76: b6e865e
- 0006-mt76-mt7915-add-the-maximum-size-of-beacon-offload.patch
- 0007-mt76-mt7915-update-mpdu-density-in-6g-capability.patch
- 0009-mt76-check-starec-newly.patch
- 0011-mt76-do-not-check-the-ccmp-pn-for-ONLY_MONITOR-frame.patch

[Release-log]
N/A

Change-Id: I985e6d5dbfd0f0fb60081b09839f3ba5ab370e8b
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6161030
4 files changed