net: phy: bcm7xxx: Fix 40nm EPHY features

The PHY entries for BCM7425/29/35 declare the 40nm Ethernet PHY as being
10/100/1000 capable, while this is just a 10/100 capable PHY device, fix that.

Fixes: d068b02c ("net: phy: add BCM7425 and BCM7429 PHYs")
Fixes: 9458ceab ("net: phy: bcm7xxx: Add entry for BCM7435")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>