net: phylink: add mac_managed_pm in phylink_config structure

The recent commit

'commit 744d23c7 ("net: phy: Warn about incorrect
mdio_bus_phy_resume() state")'

requires the MAC driver explicitly tell the phy driver who is
managing the PM, otherwise you will see warning during resume
stage.

Add a boolean property in the phylink_config structure so that
the MAC driver can use it to tell the PHY driver if it wants to
manage the PM.

Fixes: 744d23c7 ("net: phy: Warn about incorrect mdio_bus_phy_resume() state")
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>