Unused, and causes the files to be needlessly rebuilt in some cases.

This patch adds back the code that was taken out, thus re-enabling:

* The PHY Layer to initialize without crashing
* Drivers to actually connect to PHYs
* The entire PHY Control Layer

This patch is used by the gianfar driver, and other drivers which are in
development.
Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

- unexport symbols never used outside of home module
- remove dead code
- remove CONFIG_PHYCONTROL, make it unconditionally enabled

Includes fixes for problems noted by Adrian Bunk, Andrew Morton,
and one other person lost in the annals of history (and email folders).

ethernet drivers to remain as ignorant as is reasonable of the connected
PHY's design and operation details.
Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>