net: phy: Set ANRESTART in setup_forced

When configuring a PHY in fixed (forced) link mode, in order for
the changes to be applied, either one of these conditions must
be triggered:
	1- PHY is reset
	2- Autoneg is restarted
	3- PHY transitions from power-down to power-up

Neither of these is currently done, so effectively the fixed link
configuration is not applied in the PHY.

Fix this by setting the Autoneg restart bit.

Signed-off-by: Alexandre Messier <amessier@tycoint.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>