[][kernel][mt7986][timer][fix timer inaccurate]

[Description]
Fix MT7986 timer inaccurate.
Test: pass

[Release-log]
N/A

Change-Id: I32e5eb1d5ff97e68c1ac00bcf1251a052477b787
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7133509
2 files changed