net: phy: realtek: Add driver instances for rtl8221b via Clause 45

Collected from several commits in [PATCH net-next]
"Realtek RTL822x PHY rework to c45 and SerDes interface switching"

The instances are used by Clause 45 only accessible PHY's on several sfp
modules, which are using RollBall protocol.

Signed-off-by: Marek Behún <kabel@kernel.org>
[ Added matching functions to differentiate C45 instances ]
Signed-off-by: Eric Woudstra <ericwouds@gmail.com>

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>