[][MAC80211][netifd][Remove unnecessary netifd patch]

[Description]
Remove unnecessary netifd patch.
This patch was used to fix a upstream bug, which made wifi-down not
work.
Upstream had already fixed the problem so this patch can be deleted.

[Release-log]
N/A

Change-Id: I1b05110577a45372a42746aba998df1afcf98616
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8071170
1 file changed