[][MAC80211][wifi6/7][mt76][update mt76 Makefile]

[Description]
Refactor mt76 Makefile on top of the latest update.

[Release-log]
N/A

Change-Id: I63b4b8355305d175898595ba3bb2e5d5d4646d5e
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8026424
1 file changed