net: phy: dp83822: Update the fiber advertisement for speed

Update the fiber advertisement for speed and duplex modes with the
100base-FX full and half linkmode entries.

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