[][kernel][mt7981/mt7988][eth][phy: mediatek-ge: Add overflow precaution]

[Description]
Add overflow precaution for TX_AMP & R50 calibration item.

[Release-log]
N/A

Change-Id: I4d1ac86a96f3f8452cdd111b7936159d4c7a925c
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6866500
1 file changed