net: phy: marvell: Fix deadlock from wrong locking

m88e1318_set_wol() takes the lock as part of phy_select_page(). Don't
take the lock again with phy_read(), use the unlocked __phy_read().

Fixes: 424ca4c5

 ("net: phy: marvell: fix paged access races")
Reported-by: Åke Rehnman <ake.rehnman@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>