net: phy: marvell10g: differentiate 88E2110 vs 88E2111

88E2111 is a variant of 88E2110 which does not support 5 gigabit speeds.

Differentiate these variants via the match_phy_device() method, since
they have the same PHY ID.

Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>