net: fec_mxc: add PHYLIB support

net: fec_mxc: add PHYLIB support

Surround non PHYLIB routines miiphy_restart_aneg
and miiphy_wait_aneg with ifndef CONFIG_PHYLIB.
When later PHYLIB is required it is easy to delete
the non-PHYLIB code. This separation idea
came from Andy Fleming.

fec_miiphy_read, and fec_miiphy_write changed to
fec_phy_read, and fec_phy_write with argument changes.

Deprecated miiphy_register is no longer used. Both
old and new PHYLIB code now use mdio_register.

Cleanup some debug prints.

Inline function fec_miiphy_fec_to_eth is no longer necessary.
Moved to the single call location.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>