b44: rename B44_PHY_ADDR_NO_PHY to B44_PHY_ADDR_NO_LOCAL_PHY

The PHY address 30 means there is no local PHY, but there could be an
external PHY like a switch connected via MII. This is the case on most
embedded home routers where this driver is used.

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