[][Fix mt7981 patch file name typo]

[Description]
Fix mt7981 patch file name typo

[Release-log]
N/A

Change-Id: Iebcc9acd29d6e53aa286776a7990f74fe4481db7
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5184622
1 file changed