net: phy: xpcs: Return error when 10GKR link errors are found

For 10GKR rate, when link errors are found we need to return fault
status so that XPCS is correctly resumed.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>