phylink: add in-band autonegotiation support for 10GBase-KR mode.

Add in-band autonegotation support for 10GBase-KR mode.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>