ucc_geth: Fix sneaky merge conflict regarding bus_id

The patch that changed mdio_bus to a string didn't conflict strongly enough
with the patch that added fixed PHY support to UCC.  Gather it back into
the fold.

Fixes this error:
...
 CC      drivers/net/ucc_geth.o
 'ucc_geth_probe':
 /home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/net/ucc_geth.c:3935: error:
 incompatible types in assignment
 make[3]: *** [drivers/net/ucc_geth.o] Error 1

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>