b44: do not set PHY address to 30 for every ext PHY

b44_phy_reset() will fail for an external PHY and only work with the
internal PHY, this was an old workaround when the detection of an
external switch based on the PHY address failed and it is not needed
any more.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: David S. Miller <davem@davemloft.net>