net: phylink: rejig link state tracking

Rejig the link state tracking, so that we can use the current state
in a future patch.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>