net: phylink: use phy_interface_t bitmaps for optical modules

Where a MAC provides a phy_interface_t bitmap, use these bitmaps to
select the operating interface mode for optical SFP modules, rather
than using the linkmode bitmaps.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>