tsec: Convert tsec to use PHY Lib

This converts tsec to use the new PHY Lib.  All of the old PHY support
is ripped out.  The old MDIO driver is split off, and placed in
fsl_mdio.c.  The initialization is modified to initialize the MDIO
driver as well.  The powerpc config file is modified to configure PHYLIB
if TSEC_ENET is configured.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Detlev Zundel <dzu@denx.de>