[PATCH] PHY: Add support for configuring the PHY connection interface

Most PHYs connect to an ethernet controller over a GMII or MII
interface.  However, a growing number are connected over
different interfaces, such as RGMII or SGMII.

The ethernet driver will tell the PHY what type of connection it
is by setting it manually, or passing it in through phy_connect
(or phy_attach).

Changes include:
* Updates to documentation
* Updates to PHY Lib consumers
* Changes to PHY Lib to add interface support
* Some minor changes to whitespace in phy.h
* gianfar driver now detects interface and passes appropriate
  value to PHY Lib
Signed-off-by: Andrew Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>