net: phy: marvell: Refactor setting downshift into a helper

The 1116r has code to set downshift. Refactor this into a helper, so
in future other marvell PHYs can use it.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed