net: tc35815: use phy_init_hw for PHY reset

Instead of open-coding the PHY reset through MII BMCR, use phy_init_hw()
which does that for us and also makes sure that any PHY specific fixups
are applied.

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