net: phy: bcm7xxx: Add entry for Broadcom BCM7435

Add a PHY entry for the Broadcom BCM7435 chips, this is a 40nm
generation Ethernet PHY which is analogous to its 7425 and 7429 counter
parts.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>