atl1c: remove PHY reset/init for link down event

it's unnecessary to reset/init phy when link down.
Only L1/L2 chip (supported by atlx) need such action.

Signed-off-by: xiong <xiong@qca.qualcomm.com>
Tested-by: Liu David <dwliu@qca.qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>