net: dsa: mv88e6xxx: bitwise vs logical bug

We are trying to test if these flags are set but there are some && vs &
typos.

Fixes: efd1ba6a ("net: dsa: mv88e6xxx: Add SERDES phydev_mac_change up for 6390")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>