ucc_geth: Revive fixed link support

Since commit 0b9da337

 ("Rework
ucc_geth driver to use of_mdio infrastructure") the fixed-link
support is broken.

This patch fixes the support by removing !ug_info->phy_node check,
and adds a call to of_phy_connect_fixed_link() if a phy is not attached
to the MAC.

Also, remove an old fixed-link code that we don't use any longer.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>