[PATCH] powerpc: Updated platforms that use gianfar to match driver

The gianfar driver changed how it required MDIO bus and phy id's
to be passed to it.  Also, it no longer passes the physical address
of the MDIO bus.  Instead we have a proper platform device.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>