net: phy: DP83822: Add ability to advertise Fiber connection

The DP83822 can be configured to use a Fiber connection.  The strap
register is read to determine if the device has been configured to use
a fiber connection.  With the fiber connection the PHY can be configured
to detect whether the fiber connection is active by either a high signal
or a low signal.

Fiber mode is only applicable to the DP83822 so rework the PHY match
table so that non-fiber PHYs can still use the same driver but not call
or use any of the fiber features.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>