This commit adds support for Ethernet PHY drivers via a PHY API.
It also includes a driver for a generic MII compliant PHY
which supports most PHYs on the market.
Separating PHY driver from the SoC specific Ethernet driver
simplifies the Ethernet driver code and enables code re-use.
Drivers for specific PHYs with more advanced features, such as
RGMII delay in PHY can be developed independent of the Ethernet
MAC driver.
Signed-off-by: Arvin Farahmand <arvinf@ip-logix.com>
