cpmac: convert to new Fixed PHY infrastructure

cpmac: convert to new Fixed PHY infrastructure

This patch converts cpmac to the new Fixed PHY infrastructure, though it
doesn't fix all the problems with that driver. I didn't even bother to
test this patch to compile, because cpmac driver is broken in several ways:

1. This driver won't compile by itself because lack of its header describing
   platform data;
2. It assumes that fixed PHYs should be created by the ethernet driver.
   It is wrong assumption: fixed PHYs creation is platform code authority,
   driver must blindly accept bus_id and phy_id platform data variables
   instead.

Also, it seem that that driver doesn't have actual in-tree users, so
nothing to fix further.

The main purpose of that patch is to get rid of the following Kconfig
warning:

scripts/kconfig/conf -s arch/powerpc/Kconfig
drivers/net/Kconfig:1713:warning: 'select' used by config symbol
'CPMAC' refers to undefined symbol 'FIXED_MII_100_FDX'

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>